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A.K. Boomer
05-24-2008, 11:29 AM
The verdict is in, I went 255 miles on 5 gallons of gas, taking into account my odometer error (which was ever so slightly in my favor) I have by far set a new record for my car, Most of it was due to drastically changing the way I drove, but some was all the new things I just got done doing, My Progressive rate throttle design could not have turned out any better, it makes throttle feathering a Joy rather than a chore, still had to pay attention and focus but no where near as much as with the stock unit, The slight increase in tire pressure (over stock recommendations) The 0W30 syn. mobile 1 engine oil, the mobile 1 syn. trans lube (big difference just in shifting) all have contributed to this achievement --- thing is is about 15% of the 250 was city driving, and also about 15% was high speed ( 70/75mph --- too high for economy) But my car just glides down the road now, its about as friction free as I will be able to get it.
The rest was close to speed limits or 5 below where I was alone on the roads and wouldnt hold up traffic, take off was very slow and programmed, low shift points and very little throttle, stop lights were anticipated as best as possible and stop signs were also --- some coasting in area's that would permit, generally gave up about 5mph on most hills and would coast on negative if the grade permitted and speed was appropriate enough to not hold up traffic, thing im starting to notice out there is you really got to be a slug out there to hold up traffic as many others are starting to slow down or at least are more welcoming to the idea.
Told the brother with the HF (high fuel) CRX that im after him (he's rated 56mpg --- My tercel is only rated 33) His best tank is 57.4,
I dont have an air flow meter that I can trick out, but I do have a mapp sensor and a throttle position potentiometer :D Time to break out the exhaust pyrometer --- Fuels expensive, Although I dont plan on burning one up Pistons are cheap and can be replaced in a half day --- he's going down.:cool:

SGW
05-24-2008, 11:53 AM
That's really good! Driving style makes a huge difference, as does speed.

I think you're right that people are beginning to slow down.

aostling
05-24-2008, 11:56 AM
I'm inspired to try something to improve the meager 24 mpg I get with my AWD Forester. I only need FWD. I've thought about removing the driveshaft and the rear drive axles, though I doubt if this is feasible.

aboard_epsilon
05-24-2008, 12:11 PM
My LPG car usually does 31 mpg on a long run

I swapped the panel air filter for a k & n type one ...and i now get 27 mpg


my car is fuel injection ...and i don't completely understand how this works

if it was a carbed car the less restriction of the air filter would have made the fuel consumption less ...
if this new fangled computer controlled fuel injection system ...makes that miss-judged adjustment to mpg with this new filter ...can it be assumed that restricting the filter more would increase my mpg ...eg putting some more oil on it ...the filter was new dry and un-oiled when i got it ...well just the makers primed oil on it ...not much.

all the best..markj

A.K. Boomer
05-24-2008, 12:21 PM
Thanks SGW, My bro was running premium too, and he was also on a long flat trip, I had to stay semi local and theres a price to pay for all the ups and downs plus I burnt the cheap stuff...

Aostling, weve talked about your surbaru on here before -- Yes you could see some improvement by yanking the rear axles out and the propeller shaft, But I think they may have a slide in yoke with the prop shaft and if so you would either need to leave it in or come up with a way of keeping the end piece in as without it you will immediately lose all your fluid, You cannot just separate the joints either as they are "permanent"
Subarus are not a great car to try and achieve great results in, If its a manual trans it means you have a viscous coupling inside the transaxle, this is always fighting itself as its designed to handle the deviation between the front and rear diffs, so even going down the highway it can be a hinderance due to deviations caused by loads/more weight on front/tire pressures ect.ect.
The automatics are electronically controlled and I believe dont use the viscous, but they have their own set of problems when it comes to efficiencies, Even If you yank everything out of the back your still at a disadvantage in a subaru simply for the fact of the ring and pinon layout, its 90 degree's and therefore is already starting at a disadvantage as compared to the typical Front wheel drive car, Still, your biggest problem by far is subies all time 4wd, I can see why youd want to get rid of it living where you live, perhaps you could hit a salvage yard, get the prop nose off of a beater and design a way of anchoring it on the trans splines so you could leave the entire prop. (drive) shaft off and then yank your axles (I think they just unbolt) ------If this was done and you had a manual trans I would expect to see a couple/3 mpg improvement on the highway...

A.K. Boomer
05-24-2008, 12:30 PM
Aboard, Was the K&N designed specifically for your car? Does it have the same amount of surface area as your old filter? Iv seen many that were actually more restrictive, Also, do you have an ambient temp sensor? did the K&N change the relationship of incoming air (perhaps different plumbing or voiding the pre-heat?)

I havent bought a new air filter in years -- just keep backflushing my old one with compressed air (must be working!)

A.K. Boomer
05-24-2008, 12:46 PM
Aostling, If your serious -- instead of incorporating the stock part to seal against the stock seal here's a thought, remove the seal entirely, machine a cupped aluminum piece that excepts an O-ring and slide it in the end of the trans ------ done deal - dead end, Make two O-D's, one for the O-ring and one to mimmick the inside trans bearing I-D (get measurement off prop shaft)
This is just in case the internal plain bearing has a feeder hole (automatic trans?) In which case you want to put a wall against so you dont run low pressures and starve other parts, just leave plenty of I-D room on the plug for the trans splines that need to work freely. You would still need a fail safe to retain the plug, but much less complex than trying to anchor the rotating endpiece.

Paul Alciatore
05-24-2008, 12:48 PM
Congratulations on your achievement. We should all work on mileage. Real improvements, not smoke and mirrors stuff.

Your comments about anticipating traffic lights bring up a point I have thought about for a long time. How often do we sit at a traffic light waiting for it to change when there is absolutely no reason for sitting there. No cross traffic. None even in sight. And just as the STUPID light changes, several cars appear in the cross lanes and have to also stop and wait. Isn't it about time that we insist that our city, county, and state governments start using some intelligence in setting up the traffic signals.

hitnmiss
05-24-2008, 01:03 PM
AK, your comment on people driving slower or tolerating slower driving to time lights hit home with me.

I recently bought a Suzuki Samurai "jeep" big tires (for a Samurai anyway) and VERY underpowered. Last week I was driving thinking the Samurai had more power but I think it's people finally slowing down a little.

You variable throttle thread had a comment about cycling and driving habits. I bike about 100 miles a week and these hit home too. Not flooring up a hill and saving some for the downhill just like cycling helps mileage alot.

fasto
05-24-2008, 01:28 PM
I'm inspired to try something to improve the meager 24 mpg I get with my AWD Forester. I only need FWD. I've thought about removing the driveshaft and the rear drive axles, though I doubt if this is feasible.
You've got a center differential so this won't work.

(edit) Let me rant a bit about full time 4wd/awd vehicles. Even here in New England the real need for awd/4wd is perhaps 3-4 days a year. My old VW, fwd, with a set of snow tires goes OK in most any amount of snow, and I can put the snow tires away when I don't need them. The snow tires and extra wheels cost all of $500 a couple years ago. It seems that most every car maker offers awd vehicles now, with every Subaru and Audi having awd. Ford, Mercedes, Chrysler, and the rest have models with available awd. 100% of the time awd adds weight and reduces economy - it's hard to determine now much - and also increases initial purchase price. But it sells well! And the first cars off the road in a snowstorm around here are the awd ones, as awd only helps acceleration and not braking or turning!
--
Aaron

fasto
05-24-2008, 01:43 PM
My Progressive rate throttle design could not have turned out any better, it makes throttle feathering a Joy rather than a chore, still had to pay attention and focus but no where near as much as with the stock unit

That's called "Tip In". On cars with low power engines the manufacturer usually sets up a very fast "tip in" so that the car feels like it has more power. On serious off-roaders - XJ Cherokees and such - the "tip in" is very gradual so that you can easily inch the thing along without fear of spinning the tires. Some vehicles, Land Rover I think, that have electronic throttles have driver-adjustable "tip in".

My car is a 15-year old VW complete with ~200k miles, 2.8L engine, and 5-spd trans. VW give a range of tire pressures and let the driver sort it out. I find that keeping the tires at the max recommended pressure which is 44/40 gives noticably more MPG's. The low end pressure is 35/30.

I recently did a ~700 mile round trip and averaged 32.1 MPG highway being reasonably careful with speeds and such. The average speed recorded by the trip computer was 63 MPH. The car is rated at 24/28 MPG but I installed a lower ratio final drive a few years ago to drop engine RPM's on the highway. I always use full throttle acceleration when merging and such on the highway on the theory that the fuel usage is high but the duration is very short and I'm less likely to get pasted by someone driving an 8,000 lb suv.

The key to improving nationwide mileage in the US is to minimize vehicles idling and not moving where they get 0 MPG. This is the real advantage of a hybrid that can shut down the IC engine but few do this.

aboard_epsilon
05-24-2008, 01:45 PM
Aboard, Was the K&N designed specifically for your car? Does it have the same amount of surface area as your old filter? Iv seen many that were actually more restrictive, Also, do you have an ambient temp sensor? did the K&N change the relationship of incoming air (perhaps different plumbing or voiding the pre-heat?)

I havent bought a new air filter in years -- just keep backflushing my old one with compressed air (must be working!)

it wasn't a k & n it was a "green" air filter ..these are supposed to be as good as or Superior to k & n ..

http://www.greenfilters.co.uk/index.html

US SITE


http://www.greenfilterusa.com/

it was designed as a direct replacement for the stock filter ..and is the same size and fitment as old.

all the engine has is a manifold air temp sensor ...mapp sensor pipe going to the ecu and throttle position sensor and stepper motor thing on throttle ..thats it ...other than the usual 02 sensor .......coolent temp sensor , knock sensor and vacuum operated fuel pressure regulator..

LPG injection piggy backs off the standard fuel injection ...with lots of adjustment possible either way ..via laptop .

i know what you're going to say .get your laptop out ...


that's not easy ..requires two people .one to drive and one to adjust on laptop .,cant find any one to drive ..so i have to ...and the only person i can find to use the lap top is too stupid to understand how to adjust it .

All the best......markj

fasto
05-24-2008, 02:04 PM
I recently bought a Suzuki Samurai "jeep" big tires (for a Samurai anyway) and VERY underpowered. Last week I was driving thinking the Samurai had more power but I think it's people finally slowing down a little.

Heavens! I had one of these which I bought new in 1988 just after the flip over scare. $6100 for a 1988.5 model, red with a white top. Every other color was $6000 even. Sticker price on mine was $9000.

1.3L 63 HP engine with the aerodynamics of an outhouse. Low gearing - mine was a 5-speed - and I could outrace anything up to about 30 MPH. Max highway speed was around 85 MPH on flat ground and 60 MPH up steep hills. At 85 MPH mine was turning 8300 RPM in 5th gear. In 4wd high range top speed was around 50 MPH on flat ground.

We passed this car down to each new driver for years. I don't believe that we ever did any significant maintenance. My brother hit a firetruck (!) with it knocking the mirror off the pass side door and I got rear ended in front of the police station in Worcester MA (easily fixed). Eventually my dad's 2nd wife ended up with it, and then it was stolen and vanished.

Change the spark plugs frequently for best performance.
--
Aaron

A.K. Boomer
05-24-2008, 02:07 PM
Congratulations on your achievement. We should all work on mileage. Real improvements, not smoke and mirrors stuff.

Your comments about anticipating traffic lights bring up a point I have thought about for a long time. How often do we sit at a traffic light waiting for it to change when there is absolutely no reason for sitting there. No cross traffic. None even in sight. And just as the STUPID light changes, several cars appear in the cross lanes and have to also stop and wait. Isn't it about time that we insist that our city, county, and state governments start using some intelligence in setting up the traffic signals.


Thanks Paul, I really never thought Id get this far with it without any engine modifications, now its time to take it into that arena --- not going to go crazy --- I did burn a hole in a saab piston when I was a teen.

I hear you on the traffic lights, The larger cities in my area seem to do much better for the most part, Mine in my little town suck --- there could be better planning and less waste, there could also be more load sensors installed at traffic lights, sometimes i see them and they still dont seem to be working (maybe my cars to light to set them off)
If you pull up to a light and see that the pavement has cuts all around it that means its a load sensing light, If no traffic goes over it the light quickly changes back to let the other direction go,
If im incorrect on this someone please let me know, its just observations on my own as I wondered what was triggering lights at different intervals and noticed anytime this happened I seen cuts in the pavement where vehicles stop, I believe that stopping on one of these sections will trigger the light to change over in your favor if the light has been green for the other direction for awhile.

A.K. Boomer
05-24-2008, 02:23 PM
all the engine has is a manifold air temp sensor ...mapp sensor pipe going to the ecu and throttle position sensor and stepper motor thing on throttle ..thats it ...other than the usual 02 sensor .......coolent temp sensor , knock sensor and vacuum operated fuel pressure regulator..



All the best......markj



Mark, The only real potential that youv changed is the breathability of the engine --- there is one connection and it works in the way that could actually make your engine use more fuel (instead of less --- like a carburated engine usually would) The connection is your Mapp sensor, the mapp sensor keeps tabs on intake manifold vacuum/pressure --- when you introduce an airfiltration system that flows better it can actually have an adverse effect when dealing with certain systems -- in all actuality it can mimmick a lower vacuum situation and lead the computer to believe that its kinda like a throttle plate being cracked open more than what it really is ----------- this will not effect economy in a low demand mode very much at all ( because even a poor filtration device will flow OK down low therefore your mapp sensor will experience same old same old) but if you use much of your engines displacement capacity it can effect things greatly, The TPS is there to keep things real but its ultimate influence is compromised by the mapp sensor.
Just something to think about.

fasto
05-24-2008, 02:33 PM
If you pull up to a light and see that the pavement has cuts all around it that means its a load sensing light, If no traffic goes over it the light quickly changes back to let the other direction go,

These are actually inductive loops. They work very well for lights where infrequent cross traffic is present. Here, in Westborough, MA we have a few locations where a long line of cars may queue up to take a "protected left" across traffic, and inductive loops are set up so as to lengthen the time the left arrow is active based on the length of the queue of cars.

A.K. Boomer
05-24-2008, 02:47 PM
You've got a center differential so this won't work.


Aaron


Aaron, Its been awhile but iv been into both subies automatic and manual trans, There is no center Diff. The manual has a viscous coupling and used the weighted wheels (front) as the primary and the rear as secondaries allowing the coupling to take up the slack -- only two diffs (front and rear)

The automatic uses an electronically controlled trans with a 4WD hydraulic actuated clutch pack, no center diff --- no viscous coupling.

Things might have changed but this was just a decade ago anyways...

EDIT; Scratch that info about the manual --- I must be going way back to the early "shift engauge" 4wd trannies, You are correct Aaron --- I just checked into it and they do indeed fit BOTH the Diff and the viscous into the same unit.

EDIT_EDIT; Aostling, You would have to check into it with the automatic -- still could be feesable ,Im almost positive I didnt recall another diff or viscous in it but its been along time ago, The Manual would be a NO-NO without some major mods (internal) and to find a 2WD subie trans is like finding a hens tooth, actually I dont recall ever seeing one.

A.K. Boomer
05-24-2008, 02:50 PM
These are actually inductive loops. They work very well for lights where infrequent cross traffic is present. Here, in Westborough, MA we have a few locations where a long line of cars may queue up to take a "protected left" across traffic, and inductive loops are set up so as to lengthen the time the left arrow is active based on the length of the queue of cars.


Thanks for that, so they are kinda using them as a metal detector?

they must just cut the pavement and install a little wire down the groove?, I had half of it right anyhow:p

Much more cost effective -- makes allot of sense...

aostling
05-24-2008, 03:13 PM
Aostling, If your serious -- instead of incorporating the stock part to seal against the stock seal here's a thought ....

Boomer,

I recall the scenario you described many months ago, when you had to tear down an engine three times to fix some vexatious problem. If I attempted something like you describe for my Forester I'd be off the road indefinitely. I'd be tempted if it was an easy modification, but I see that is not the case.

At current gas prices, if my mileage improved from 24 mpg to 27 mpg, that would save me about 2 cents/mile, or $1000 in the next 50,000 miles. A conversion, done professionally, might have some customers.

aboard_epsilon
05-24-2008, 03:27 PM
Mark, The only real potential that youv changed is the breathability of the engine --- there is one connection and it works in the way that could actually make your engine use more fuel (instead of less --- like a carburated engine usually would) The connection is your Mapp sensor, the mapp sensor keeps tabs on intake manifold vacuum/pressure --- when you introduce an airfiltration system that flows better it can actually have an adverse effect when dealing with certain systems -- in all actuality it can mimmick a lower vacuum situation and lead the computer to believe that its kinda like a throttle plate being cracked open more than what it really is ----------- this will not effect economy in a low demand mode very much at all ( because even a poor filtration device will flow OK down low therefore your mapp sensor will experience same old same old) but if you use much of your engines displacement capacity it can effect things greatly, The TPS is there to keep things real but its ultimate influence is compromised by the mapp sensor.
Just something to think about.

aha

so restricting the air intake to the air filter ...will have an effect in the region of load and rpm ...where the trouble is

so if i experiment with doughnut shaped restrctors ...i may end up with a compromise ...
i don't use the engines max power that often ......but the mid range can be adjusted back to stock with a restrictor .

all the best.markj

A.K. Boomer
05-24-2008, 03:28 PM
Yeah Aostling the Mitzu VR4 had a total of 3 diffs and one viscous coupling --- im even forgetting its drivetrain layout some (thank god)
A good service book will give you the whats what, Aarons correct, the first google I found on the manual showed both the internal diff and the breakdown of the viscous, sorry, I hope I didnt get your hopes up (it looked to be an outback sedan)

But -- if you do have an automatic then I would think you could still achieve it if you wanted --- i remember a clutch pack at the rear of the trans for the 4wd --- it was computer controlled hyd. actuated (in fact the reason i had to go into it was because the hyd. pipe broke and the 4WD went kapooey)
So the very fact that it gets disconnected and reconnected by the clutch pack tells you that it can function without it - because it does normally until wheel slip is detected.

SGW
05-24-2008, 03:58 PM
The best I ever did in a Subaru Outback on my 70-mile commute was just under 28 mpg. When I got a Toyota Corolla, I was managing 40-43 mpg on the same commute. Subarus don't get great mileage.

Whoever it was a few posts back who questioned the need for AWD...yeah. I *liked* having the Subaru AWD, but I got four real snow tires for the Corolla (snow tires, not "all-season" tires) and have never had a problem, either. Even with four extra wheels, it wasn't outrageous money.

bob ward
05-24-2008, 04:18 PM
Then there is the story about the guy who added every possible aftermarket mpg improver to his car.

Polished the car with the aerodynamic NASA polish to get an extra 7%
Fitted the 'race track proven' spoiler kit guaranteed to give another 17%
Fitted the low rolling resistance tyres for another 11%
Filled the tyres with dry nitrogen for an extra 4%
Added the steering sabiliser to gain 6%
Filled the engine, gearbox and diff with the low friction additives, each claimed to add 18%
Added the low resistance air cleaner to gain 7%
Installed the atomic/magnetic fuel particle aligner for another 11%
Installed the new miracle carby to get a whopping 32%
And even the 'scientifically designed' low weight battery for another 4%

He got 10 miles down the road and his fuel tank overflowed. :D

jdunmyer
05-24-2008, 08:18 PM
Slowing down and taking it easy on acceleration are the real keys to increased fuel mileage. In the past month or so, I've noticed that when towing my trailer, I'm often passing trucks when at my usual 60-61 Mph cruising speed. That almost never happened last year.

Towing at 62-63 will lower my mileage by at least 1 Mpg, from 13.5, down to 12.5. ('01 Dodge Diesel, towing an 8000# Avion travel trailer)

Interestingly, I hauled some parts racks on a flatbed trailer a couple of weeks ago. These are heavy wire mesh (1/4" and 5/16" rod), about 4' square, they were stacked 2 high, and I had 3 stacks. The fuel mileage computer showed between 9 and 11 Mpg, and the boost and pyro guages indicated that the engine was working harder than when towing my travel trailer. Moral of the story: get rid of those bug deflectors and "eyebrows".

When I first got my 2000 Jetta TDI (Diesel), I drove it about like I did my 1991 Jetta: ssllloooooowwwly on takeoff. Mileage was a whole lot better than later on when I got used to having a bit of performance under my right foot. :-(

A car I think is really disappointing is the Smart Car. Those things get barely over 40 Mpg. I had a Honda 600 Sedan back in 1972 that did that well, albeit with nowhere near the performance. Can you say "Slug"? I knew you could.

J Tiers
05-24-2008, 09:52 PM
Drove 500 miles since Friday.......

New record mileage here too.... The truck got 27 mpg, WITH 10% Ethanol fuel, and it is rated at only 29 under the OLD EPA ratings........ which are accepted to be BS.

Previously got 24 to 25 MPG. Not a huge increase, but it DID let me get through the expensive gas states where I might have had to stop before.

What did I do?

I didn't drive at 75 MPH...... didn't go over 65, mostly 58 to 62.

The key for me is driving ONLY while wearing western style shanked boots ("cowboy" boots for those from elsewhere).

The advantage is that I just get my foot where it automatically holds the pedal at the right spot.... Let it slow down a bit up hills, faster down hill.

Cheaper than a cruise control, and does not tend to speed up going uphill, which wastes gas.

Dawai
05-24-2008, 10:06 PM
http://img.photobucket.com/albums/v85/ibewgypsie/DSCN0088.jpg
Honda FIT.. 1.5 vtec engine.. gets 38mpg at 85mph.

With some of the people I know who have SUV's.. they could have one of these for the loss of money through the tail pipe. Price was $14,500 new.. insurance was same as the honda civic. Actually more room inside than a civic, the rear seats fold down, the front seat folds down to carry 8' 2x4's.. or make a ambulance or..??

aostling
05-24-2008, 10:40 PM
Honda FIT.. 1.5 vtec engine.. gets 38mpg at 85mph.


That looks pretty spiffy. The new model http://onlocation.consumerreports.org/New-Car-Preview/2-Model.asp?ID=785&__Honda_Fit may fit my 6' 3" frame, since it has more leg room.

Dawai
05-24-2008, 11:56 PM
Ohh FIT mods by David include Castrol Syntec motor oil and high flow filters.
I took it to Illinois recently with about three hundred pounds of stainless, a harley frame, and about six hundred dollars in chrome parts.. It just hummed.. Not exactly a cadillac thou riding back in the heavy rain, you realize you are the smallest roller skate in the middle of 18 wheelers. I DID Not get near that mileage on the way up, but coming back I got excellent mpg again... I had a harley softail frame coming home and my large rear..

Yes, My six foot four buddy bangs his head getting in.. I am six one and three hundred pounds and get in and out just fine.. NOW.. the CRX with the roll bar across the door.. another whole story.. I may take a youtube video of me getting in just for the fun of it.. You guys probably need a good laugh..

Mileage is a combination of weight, mechanical efficiency and air resistance.

I had a 327 in a vega that got 25mpg. THE four banger got about 25 miles to the quart of oil...
Had a 69 camaro that got that most the time (gas). then I put this high rise aluminum intake, and a 650 dp holley on it and it got about 15... THE large plenum intake I think killed the atomization and slowed the intake mixture speed.

You do have to size a radiator to efficiency and horsepower thou.. otherwise.. it looks like a stanley steamer when you use that horsepower. Most gas engines are terrible on efficiency and waste a lot of heat.

A.K. Boomer
05-25-2008, 12:41 AM
Mileage is a combination of weight, mechanical efficiency and air resistance.

.


And that covers about half of it -- the rest is driver input.

Dawai
05-25-2008, 02:16 AM
AK..

Now mechanical efficiency goes way down with poor throttle control. I took that as a given.

The first time there was a purported gasoline shortage.. *ha.. I installed a vacuum guage from a early 60's oldsmobile in my car.. you could keep the vacuum up, and keep the gas mileage up. It amounted to acting like a egg was under the throttle.. and really slow depression. I had at that time a 66 nova with six cylinder. I went from a 68 Dodge Dart GTS 383 to a nova w/powerglide.

All this new "gas shortage is" ... well I was watching a special on Osama Ben Ladin.. he was going to start a war on America cause we were keeping the price of fuel down.. I guess he has won the war? perhaps this so called Muslim politician presidential hopeful can talk to him?

bobw53
05-25-2008, 02:49 AM
A car I think is really disappointing is the Smart Car. Those things get barely over 40 Mpg. I had a Honda 600 Sedan back in 1972 that did that well, albeit with nowhere near the performance. Can you say "Slug"? I knew you could.


I was in Dallas a few weeks ago, and saw a few "smart" (the a@@holes selling them maybe) cars driving around, so I looked them up. HUGELY disappointing. 41mpg hwy, 32? city, average of about 36mpg. What the hell is that???? From the size I was figuring an easy 60mpg. What an absolute crock of sh!t!!!!

If you guys don't mind, this fuel thing is really driving me nuts, so I'm going to vent on a few things that have really pissed me off over the past 10 years or so.

'94, had a motor rebuilt(I was young and dumb and in college, done all my own since) for my Bronco, '78(the big ones) lifted 4" 33X12.5" tires. The engine guy wanted to know what I wanted for a cam, I wanted LOW end. Fell on its face at 4000rpm, but I could run it down to 200rpm and still get going again without a problem. 14mpg around town, 17mpg at 68mph on the highway, the new Broncos at the time were doing 8 and 12. WTF. Does a backyard monkey mechanic know better than Detroit?

'96 -'98 '75 280Z. Stock motor, 150hp net, 170gross. Getting 18-19 city 22-24 hwy. Rebuilt the motor, and upped the horse, light porting, basically just cleaning it up, added a header, and reasonable cam. On my benchmark run from the intersection to the railroad tracks, I went from 53mph with the old motor to 78mph by the time I hit the tracks. Mileage went to 22 city, 27 hwy. How the hell does that work, and I WAS NOT light footed with it. Mileage around town probably would have been higher if the tires weren't spinning so much. That motor with less than 30k is currently being resurrected into a rust free '76 body, I can't wait.

A friends '69 Datsun 510, 1.6l. well into the upper 30's. That was in 1969, and we can't do any better 39 years later????

The one that really irked me just the other day. We were stripping all the goodies out of a street sweeper. It was a trade off, we got to strip it, if we towed it 3 miles to our shop and used our forklift to load it on a lowboy so it could be scrapped. Grabbed a Dodge 318 that we needed for one of the toys in the yard (Ferrari tractor), hydraulics(pumps, motors and cylinders), and a 14A datsun motor and tranny that was running the ass end of the sweeper. Looked up the 14A motor since I was only familiar with the L-series, and there was a 14A "high mileage" motor in a Datsun/Nissan B210 somewhere around the early '80s that was getting 47mpg.

I think that motor is going to find its way into an old Spitfire or MG, just to see what it can do for mileage, maybe a tweak or two, aftermarket injection maybe.

Are we going backwards or what. High mileage is now in the 30s? Thats a bunch of crap. There is no reason that stuff rolling off the assembly line shouldn't be up in the 60's, especially the fricken "smart" car.

If any of you guys are into the high mileage thing(and I can tell you are), check out he new X-prize. 10million$$ for a 100mpg car. The rules aren't finalized yet, entry fee is $1000 refundable if you don't compete. I really don't think its all that difficult.

http://www.progressiveautoxprize.org/

Notice how you don't see any oil or car companies sponsoring it????

Boomer keep it up, that is some good stuff.

Dawai
05-25-2008, 03:00 AM
Bob:

Now if you are close to the SOUTH east USA? I got this mg midget with a 9" ford rear axle narrowed in it..

It with a 5 speed would be unbreakable.. and fun..

A.K. Boomer
05-25-2008, 10:12 AM
BobW --- if you could talk to my friends they would think that what you just wrote sounds allot like me talking, I cannot for the life of me figure it out either, We have and already have had some great examples in the past --- like I said my bro's HF CRX is rated 56mpg --- thats gas, and thats 1990, almost 2 decades have past, two of the most explosive tech. breakthrough decades ever to exist on the planet (that we know of:p )

What the hell? I too am amazed at the "smart car" I think its really the dumb car for what they charge and what it does,

If I had to try and make an attempt at the 100mpg car I might try it with something like the HF CRX and tons of mods, Exhaust pyrometer, ceramic coated pistons, adjustable mixture control, skinny high pressure and very tall tires --- yet drop the springs so she sits much lower than stock, half moon covers over the rear wheel wells, syn. lube everywhere, although there only 1,800lbs i would gut it out to 1,500, there is many other little things, It could be achieved quite easily - if you get to choose the speeds and conditions, Depends on what they want - I can lean out my tercel and achieve close to that right now (also driving at 45 mph), It wont do it day in and day out, it will have a hole in the piston before too long,
The CRX is pretty slippery -- they could put the air back together a little better but theve got a good CD rating, also all it would take is a little 500cc diesel to push it along at highway speeds, or you could turbo diesel a little 250cc, Im going to go check out that site as it sounds interesting, there will be an up side to the higher fuel prices, there has to be change now -- we have no choice. (and its not going to come from "the smart car")

aboard_epsilon
05-25-2008, 10:28 AM
That's lousy mpg on the smart car ...

You sure somethings not getting lost along the way in the trip computer ...and the American small gallon verses the European large gallon...perhaps the engineers got the sums wrong.

I used to get 55 mpg out of a 1978 1.1 litre ford fiesta on a long run......this was with an ancient two valve, OHV ,carb engine.

All the best....markj

aboard_epsilon
05-25-2008, 10:39 AM
I dont know where you got those mpg figures from oin the smart car .... says here ...a very repected site...a different set of figures.

http://www.whatcar.co.uk/used-car-costs.aspx?RT=2426&type=4


Running costs are very low, though. The older cars will return an average of 57.6mpg or 55.4mpg depending on the engine you go for, and the newer cars can just creep over the 60mpg mark. Even the Brabus version will return a highly respectable 53.3mpg.
Insurance costs will be equally meagre. For any mainstream ForTwo, you'll pay a group 2 premium. However, as Smart is a part of the Mercedes stable, costs for routine maintenance are uncommonly high in comparison to other city cars'.


And NOTE it says "avarage" ...not best

all the best.markJ

JCHannum
05-25-2008, 11:02 AM
Posted EPA mileage figures for 2008 are 33 city, 41 highway. YMMV.

http://www.smartusa.com/smart-car-technical-specifications.aspx

aostling
05-25-2008, 12:30 PM
I'm wondering what will happen to all the big vehicles which get 12 to 15 mpg, the Suburbans and F150s. You just know that in a year or two they will be unsellable.

It takes energy to crush them, and more energy to melt them down. Maybe the only solution is to take them out to sea and dump them (after a cleansing) -- they do make a good reef for fish.

aboard_epsilon
05-25-2008, 01:34 PM
I'm wondering what will happen to all the big vehicles which get 12 to 15 mpg, the Suburbans and F150s. You just know that in a year or two they will be unsellable.

It takes energy to crush them, and more energy to melt them down. Maybe the only solution is to take them out to sea and dump them (after a cleansing) -- they do make a good reef for fish.

well any one who has got their head screwed on will work out

that the crap cheap prices .you will be able to pick these up at, in a few months time ...will equal the price rise on fuel ...if you do average mileage.

so maybe a good opportunity to get your self something you've always wanted. :)

all the best.markj

tmarks11
05-25-2008, 02:10 PM
Let me rant a bit about full time 4wd/awd vehicles. Even here in New England the real need for awd/4wd is perhaps 3-4 days a year.
Reminds me when I was car shopping in 1995 in Connecticut... went and drove a new Chevy Blazer, and asked thealeman pricing for a 2WD version.

He said I was crazy, that you need a 4wd in CT, ad that they wouldn't sell 2WD.... that I didn't know what I was talking about. Of course, gasoline was about $1.6 per gallon then (and $0.95 everywhere else in the country... but that is a different story), so my desire for better gas mileage didn't hold any water with him.

Amazingly enough, I managed to drive a Dakota pickup for years and years without ever sliding off the road in New England (even without weight in the back). In 5 years, I think there was one time I wished I had 4wd, when I was trying to get into my driveway over the hump of snow left by the snowplow.

Back OT, my 17 mpg is getting old, so I am guessing it is time to shop for something smaller. It is crazy that the turbo/supercharged small diesels aren't available here like they are in Europe. Forget hybrids, you want good gas mileage get one of the small VW diesels. I remember my parents getting 50+ mpg with a diesel Jetta in the 90's. Guess at $11 per gallon for gas, Europeans are way ahead of us in their quest for fuel efficiency.

Scishopguy
05-25-2008, 02:19 PM
I have always liked a pickup truck because I am constantly hauling crap around, lumber to use on the house, steel scrap that I can scrounge, and lawn mowers going to the shop. Now most if not all pickups have rear ends that are geared for power at the low end for towing, hauling heavy stuff, and off road use. Maybe I am missing something here but I could never understand why they never had the option of a 2 speed rear end. Most of the time you don't need the towing or hauling power and are just driving somewhere but when you need it, you really need it. Best little truck I ever owned was a Datsun King Cab ('78) with the 19XX CC engine and 2bbl carb. That thing got 23 mpg around town and 28 mpg on the highway with no mods or even close attention to tire pressure. I think there is a lot more the auto companies could do if they had a gun to their heads. Not for fear of being painted as a paranoid I'd even suspect that the car makers are "in bed" with the oil companies keeping the mileage figures down until the oil guys can corner the market on the next energy source, be it hydrogen or whatever.

Rant mode off

bobw53
05-25-2008, 03:05 PM
David E Coffer, that sounds like fun, but I don't think its worth the trip from New Mexico.



I dont know where you got those mpg figures from oin the smart car .... says here ...a very repected site...a different set of figures.

And NOTE it says "avarage" ...not best

all the best.markJ

The UK/European version, certainly not the US version, which is a joke.

I don't get it, roughly the same horse power, 200lbs difference in weight, I understand the UK gallon is slightly larger, but its not twice as big. Makes me sick.

Dawai
05-25-2008, 03:31 PM
I sent that harley panhead to Arizona for $600.. buyer paid.. this mg midget is about as heavy, but larger.

Ok.. It may or may not be at the shop now.. they have been stealing everything scrappable.

Lighter cars, slippery cars, new combustion techniques.. the Hydrogen peroxide injected diesel would work out just fine.. like the nasa rocket, it ignites the diesel and burnes clean blue flame.

A hydrogen peroxide steam car, the boiler could be the size of a lunchbox.. all you do is inject it across a silver nitrate screen pack to expand it to steam.. really.. no pumps no extra junk.. add in some instrumentation to keep it from over fueling, add in some pop off valves if something goes awry.. add in a few more lil tidbits and you got a viable fuel for competetion with gasoline at it's present price.. now at it's future price for damn sure..

Problems? well the silver screens erode throwing metallic particles into the steam.. so a good filter would have to be developed.. It is no more explosive than gasoline on a hot day.. Do you realize we have all driven around with a gasoline bomb in under our cars??? just watch the saturday night flicks to see them explode.. they never do it seems in real life..

David

Mark Hockett
05-25-2008, 03:57 PM
My LPG car usually does 31 mpg on a long run
I swapped the panel air filter for a k & n type one ...and i now get 27 mpg
my car is fuel injection ...and i don't completely understand how this works

all the best..markj

Mark,
If your vehicle is equipped with a certain type of Mass Air Flow Meter the oil from the K&N will contaminate it and cause the problem you described. I have replaced quite a few Air Flow Meters because of this.



Yeah Aostling the Mitzu VR4 had a total of 3 diffs and one viscous coupling --- im even forgetting its drivetrain layout some (thank god)
A good service book will give you the whats what, Aarons correct, the first google I found on the manual showed both the internal diff and the breakdown of the viscous, sorry, I hope I didnt get your hopes up (it looked to be an outback sedan)

But -- if you do have an automatic then I would think you could still achieve it if you wanted --- i remember a clutch pack at the rear of the trans for the 4wd --- it was computer controlled hyd. actuated (in fact the reason i had to go into it was because the hyd. pipe broke and the 4WD went kapooey)
So the very fact that it gets disconnected and reconnected by the clutch pack tells you that it can function without it - because it does normally until wheel slip is detected.


On automatic transmission Subaru's there is also a single fuse holder on the passenger side under the hood marked FWD. Installing a 15 amp fuse in this holder will turn off the AWD and make the vehicle a FWD vehicle. I wouldn't get your hopes up of installing a fuse in the holder and getting better fuel mileage, I had a coworker who had 60 mile one way commute and he tried this, his fuel mileage did not change. The reason for this is the drive train is computer controlled and power is rarely sent to the rear wheels under normal driving conditions, I have driven these with the factory scan tool connected and watched the percentage of rear axle application and it is usually not applied.

aboard_epsilon
05-25-2008, 04:43 PM
Mark,
If your vehicle is equipped with a certain type of Mass Air Flow Meter the oil from the K&N will contaminate it and cause the problem you described. I have replaced quite a few Air Flow Meters because of this.

it does not have a mass air flow gadget

only an air temp sensor

that is the same as this ...

http://img.photobucket.com/albums/v190/aboard_epsilon/aa89_1.jpg

think only the diesel models of my car have the mass air flow gadget .

all the best.markj

A.K. Boomer
05-25-2008, 09:55 PM
On automatic transmission Subaru's there is also a single fuse holder on the passenger side under the hood marked FWD. Installing a 15 amp fuse in this holder will turn off the AWD and make the vehicle a FWD vehicle. I wouldn't get your hopes up of installing a fuse in the holder and getting better fuel mileage, I had a coworker who had 60 mile one way commute and he tried this, his fuel mileage did not change. The reason for this is the drive train is computer controlled and power is rarely sent to the rear wheels under normal driving conditions, I have driven these with the factory scan tool connected and watched the percentage of rear axle application and is is usually not applied.

Mark, I remember you from a while back and we talked about subies head gasket problemo's, My comment about the automatic was not just about leaving it out of the 4wd mode, it had to do with yanking all the guts out that are causing the extra drag, If he got rid of the prop shaft and the axles he would see some gains, he would have to find a way to seal off the rear of the trans where the prop shaft was -------- axles eat efficiency - but gearing "up" to spin a prop shaft at close to 4 to 1 is the real culprit -- along with constantly "blending" the 90 wt. in the rear end...

Edit; but all this is just speculation, for one I dont know if he has an automatic, and two it would have to clear you as the final hurdle, you know these cars better than I do --- Could there still be a quirk? Doesnt sound like it should be a problem but he would have to know for sure before attempting -- what say you?

Double edit; Solution? put in fuse to get only Front wheel drive, pull rear axle shaft assemblies, If its like you say it totally shuts down the 4WD actuating mechanism ---- leave the prop shaft in and it just remains a stagnant piece, no diff drag no axle drag no prop shaft drag, no need to make up a seal kit for the rear of trans -------------- Very practical approach No?

fixerdave
05-25-2008, 10:01 PM
... WTF. Does a backyard monkey mechanic know better than Detroit?...

Well, if you look at the motors, you'll realise that in the mid '70s they had to lower the combustion temperature to reduce NO3 (or something like that) so as to make less smog. It was a pollution control thing. As it so happens, a really easy way to reduce combustion temperature is to ... Burn more gas. Then, to deal with the unburnt fuel heading out the exhaust pipes, they had to add catalytic converters. My '70s Datsun pickup actually pumped air into the exhaust manifold to aid combustion of the wasted gas. :mad:

By changing the cam, and by properly tuning it, you violated pollution regulations, made more smog, and got yourself a better performing vehicle. Besides that, a well running and powerful engine tends to be more efficient than an economy engine, assuming you're driving it at the same, umm, --reasonable-- speed. Push an economy box to its limits and compare the mileage to a decent machine driven at the same speeds. You'll probably get better mileage with the performance engine. Drive the performance machine at its limits and, well, you're going to pay for the fun.

Personally, I kind of like it when gas prices go up. For a couple of weeks, the traffic pattern gets noticeably lighter. Everyone freaks out and starts walking or riding the bus. It's great for me :D Nobody's in my way. Then, people slowly start to realise that riding the bus sucks big time, that gas isn't "that" expensive, and they start driving again. After a while, it's back to normal traffic. Then, the next price spike comes along and they do it over again. I suppose one day the spike will be so high that they just stop driving permanently. It has to happen sooner or later; hopefully I'll still be able to pay for gas.

As for me, there's no economy driving. I don't care what I'm in; I'm ripping the guts out of it. If I'm paying for gas, I'm going to enjoy every freaking mile. After all, this is the end-time of an era. I don't care how much performance you're going to get out of an electric car; it's just not going to be like getting up on the pipe with a real engine. Some day, there won't be anyone alive that actually gets Deep Purple's "Highway Star." :cool: I mean, could you imaging a pounding rock song for some electric car jock? ...I didn't think so. It'll probably be driven by a computer anyway.

David...

Dawai
05-25-2008, 11:18 PM
I'm not familiar with the engine you got.. but..

Normally if they do not have a Maf (mass air flow) sensor in the intake tube, they have a MAP (manifold air pressure) sensor in the intake.

In most instruments, a MAF has a heated wire, it measures the transferred heat downstream of the heater.. the faster the air flowing, the less heat transferred and more cooling. THE heated oxygen sensors? no clue how they work.. I've not dissected one.. yet..

I'd like to see a specially programmed ECU, using the FLy by wire throttle like on the Honda FIT, having clicker stops on it to represent speeds in 5mph increments and the ECU be set to keep vacuum up and economy stroke the throttle body PERFECT.. you could just click down to say, 45mph.. and the car would do all the economical thinking for you.. and not "waste" over 45 accelleration or do it anyway but the right way.
That is why I love Robotics and instrumentation... it does not get bored, or tired.. nor forget about things you program it to do..

fasto
05-25-2008, 11:28 PM
Personally, I kind of like it when gas prices go up. For a couple of weeks, the traffic pattern gets noticeably lighter. Everyone freaks out and starts walking or riding the bus. It's great for me :D Nobody's in my way. Then, people slowly start to realise that riding the bus sucks big time, that gas isn't "that" expensive, and they start driving again. After a while, it's back to normal traffic.

I just did a couple of calculations about this. Let's say you've got a 2008 Suburban, which gets 14.5 MPG. You drive 15,000 miles/year. You burn just over 1000 gallons of fuel (1038 to be exact :)). So, with the price of gas increased from $3.50 or so to $4.15 now, that's around $700 extra per year, or $2/day. Even if gas goes to $5.50 that's an extra $2075 or so per year, or $5.68/day. Probably by skipping the latte you'd save $5.70/day. Besides, it's a $40k vehicle, anyway!

OTOH, say I've got a VW that gets 30 mpg and I drive 15,000/year. The VW needs 93 octane but the cost increase is the same. At about twice the MPG of the Suburban I'm looking at around $1/day extra for $4.15/gal, $2.75/day @ $5.50/gal.

It really does sound like a lot of $$$$, but in actuality I think we'll need to see $10/gal before significant, permanent changes occur.

Dawai
05-25-2008, 11:34 PM
Except in Thievery.. the plastic gas tanks on all new cars open a whole new concept in getting the fuel out of them. What does a thief care if all the rest of your gas flows out into the gutter? As long as he gets his.

During the 70s.. I super glued a pair of shick razor blades onto the gas cap on my Torino (ex Chattanooga police car).. There was a blood trail out the driveway, a cut garden hose laying in the gutter with blood all over it.

THAT, however is a felony, called a man trap. I didn't get caught so I am very lucky.

Funny, driving around that old Chattanooga plain jane car lil hubcaps, short antennae, none of my long haired buddies would stop and talk to me anymore.. IT WAS FAST, a 351Cleveland. A whole lotta fun, till my wife took it in the divorce.. It only got about 15mpg..

bobw53
05-25-2008, 11:43 PM
Well, if you look at the motors, you'll realise that in the mid '70s they had to lower the combustion temperature to reduce NO3 (or something like that) so as to make less smog. It was a pollution control thing.


Maybe thats why I like that car. vin# HLS30201923, meaning the 1923rd 280Z built. So early in the production run, the fuel injection was still all Bosch(Nissan hadn't ramped up their own production yet). Oh yeah, fuel injected, Bosch L-Jetronic in 1975. No cat, No EGR, No oxygen sensor, just a PCV valve and a charcoal canister. Incredibly simple, all analog, yet very effective and reliable.

I didn't tweak anything, just cleaned up the heads, matched them to the header, and cleaned up where the mass air flow sensor went into the intake. Stock 8.3:1(or was it 8.8?) compression. Jumped about 20 degrees and .040 of lift on the cam. 278deg (238 at .050) and .470 of lift(I think, its been a while).

I did nothing remarkable except increase the power, and the power band, pulled hard from an idle up to 6k, stock didn't get going until over 3000 and fell down at 5600.

Actually, I did pull a couple of tricks on the porting of the head. "Practical Gas Flow" by John Dalton. I had a flow bench set up in my parents basement, 3 wet dry vacs plus the household vac all hooked together, I never got enough flow, but I did learn a few things.

This guy explained these things that he called anti reversal "ratchets", very simple, looks like you ran a dovetail cutter around your port. Creates turbulance at low flow which in effect shrinks your port size for more nut on the low end, and then at higher flows the turbulance gets smaller and opens up your ports. Incredibly informative book. Maybe that had something to do with the good mileage?

That book explains all kinds of good stuff. For you mileage hunters I think it might be a very good read. How to build a flow bench, how to use it, how to test what you are doing, fun stuff. E-bay had 2 of them at $65, Amazon had none I could find, but a google search popped up a bunch in the under $20 range. I paid $21.95 in june of '94.

I hadn't thought of that book in forever until I was halfway through this post, and I actually found it. I am definitely going to re-read it.

Mark Hockett
05-26-2008, 12:44 AM
Double edit; Solution? put in fuse to get only Front wheel drive, pull rear axle shaft assemblies, If its like you say it totally shuts down the 4WD actuating mechanism ---- leave the prop shaft in and it just remains a stagnant piece, no diff drag no axle drag no prop shaft drag, no need to make up a seal kit for the rear of trans -------------- Very practical approach No?

A.K.
You have the right idea, leave the drive line in and install the FWD fuse, remove the rear axles and pop the outer joints off. It is very easy to remove the outer joints by sliding the boot out of the way and hitting the joint with a hammer. Once the axle shaft is removed it is easy to remove the guts from the outer joint by rocking the joint around to remove the bearings, then the bearing cage can be removed and that will leave you with just the outer stub, then you can reinstall it in the rear hub and that will insure the proper bearing preload.

The way power is transmitted to the rear axle is through a transfer clutch in the end of the transmission near the rear slip yoke. The transfer clutch is a normal piston applied friction/steel clutch set-up just like most other automatic transmission clutches. By installing the FWD fuse that clutch will not apply. This FWD fuse is installed so the vehicle can be run on a dyno. The transmission in the Subaru is a Jatco transmission similar to the transmission in Nissan trucks, some Nissan RWD cars, or Mazda MPV vans. Subaru just puts a differential between the bell housing and the transmission body. At the end of the trans where the output shaft is they have a transfer gear and shaft that sends the power back to the front differential where you get your front wheel drive. Then to make it all wheel drive they put a transfer clutch and output shaft just like on a normal rear wheel drive car driven off the back of the transfer gear. It is a very simple system and very reliable, that is why Subaru's are one of the best all wheel drive vehicles.

BTW, I am a Subaru Master tech and have worked on Subaru's on and off since the mid 80's, I am also an A.S.E. Master tech, A.S.E. Master Engine Machinist, Hyundai Master Tech, Toyota certified and Mazda certified. I got out of it in 2005 when I moved to Whidbey Island to open my machine shop. But about 6 months ago I started working part time at a local import repair shop. They were having trouble finding a tech so I told them I would help them out until my new shop building was completed.

If you need any help or import repair specs let me know.

aostling
05-26-2008, 01:07 AM
Okay, between Boomer and Mark I see that my 2004 automatic Forester can be converted to FWD, with a mileage gain. But how much, that is the question? I would not attempt the procedure myself, but I have a friend who is a former A.S.E. mechanic, and will discuss it with him. The vehicle has 92,000 miles on it.

Charles Ping
05-26-2008, 01:12 AM
I dont know where you got those mpg figures from oin the smart car .... says here ...a very repected site...a different set of figures.

http://www.whatcar.co.uk/used-car-costs.aspx?RT=2426&type=4




And NOTE it says "avarage" ...not best

all the best.markJ

Mark

Don't for forget the US gallon is smaller than the imperial gallon.

Personally I'm glad that my Volvo V70 diesel will average UK 50mpg(UK) on a long run at 60mph. Diesel prices have just reached the equivalent of $10 per US gallon here so every extra MPG helps.

Dawai
05-26-2008, 08:16 AM
Since we got all you ASME guys holed up here.. Can I pick your brain a second?

WHY Has cars not went to a butterfly valve in the intakes to stop mixture inversion at low speeds? This seems to work well on 2 strokes. DOES the inversion promote mixture? With current vibratory atomization injectors available this should be a non-issue thing.

This would add in another percentage increase of low speed power.

J Tiers
05-26-2008, 08:32 AM
Update.....

I calculated the mileage figures instead of estimating...... got 27 mpg going East, and 29 mpg coming back west (different days).

This in a "fuel hogging "light truck" that the environmentalists would like to have crushed and shipped to china as nasty old scrap.

That truck cost me about $12,000 back in 2000. So remind me again why I should scrap it and spend $27000 on a Prius that can improve my mileage less than 2x?

As for the "wearable" "Smart car", I got as good mileage in my old VW bug as that POS seems to get. And could fit more into the bug.

aboard_epsilon
05-26-2008, 08:33 AM
Mark

Don't for forget the US gallon is smaller than the imperial gallon.

Personally I'm glad that my Volvo V70 diesel will average UK 50mpg(UK) on a long run at 60mph. Diesel prices have just reached the equivalent of $10 per US gallon here so every extra MPG helps.

right so his 50.3 mpg

would be 60 ish here in the UK (twenty percent difference in the gallons i think)

that's very good

still remembering my awful land rover that did 14 mpg

all the best.markJ

fasto
05-26-2008, 09:50 AM
Maybe thats why I like that car. vin# HLS30201923, meaning the 1923rd 280Z built. So early in the production run, the fuel injection was still all Bosch(Nissan hadn't ramped up their own production yet). Oh yeah, fuel injected, Bosch L-Jetronic in 1975. No cat, No EGR, No oxygen sensor, just a PCV valve and a charcoal canister. Incredibly simple, all analog, yet very effective and reliable.


My 280Z is HLS30370415, it's an "early" 77 model. It has the JECS (Hitachi) clone of the Bosch L-Jetronic. It has EGR and a charcoal canister, but not much else. I seem to remember that I got about 16/20 MPG with it but it has a silly cam. I pulled the 4-speed and put in a 5-speed many years ago, since I had the R200 limited slip diff the driveshaft was the same. I bought the thing on April Fools Day in 1985, drove it for years, and now it's in my dad's garage since I don't have time or space to use it anymore. Someday I'll get to it, needs brakes on 4 wheels.

A.K. Boomer
05-26-2008, 11:46 AM
A.K.
You have the right idea, leave the drive line in and install the FWD fuse, remove the rear axles and pop the outer joints off. It is very easy to remove the outer joints by sliding the boot out of the way and hitting the joint with a hammer. Once the axle shaft is removed it is easy to remove the guts from the outer joint by rocking the joint around to remove the bearings, then the bearing cage can be removed and that will leave you with just the outer stub, then you can reinstall it in the rear hub and that will insure the proper bearing preload.

Damn, thats what I was afraid of -- I know the rear axles unbolt at the diff and was hoping they did the same at the wheel drive, so what your saying is that the outer joint is like the fronts and are a splined shaft that runs through the hub, in this case it would have to be left in and all the CV guts removed, Its still a hassle but if I lived in arizona I would do it in a second, Was just hoping it was bolted on the outer flange as well, Then Aostling could get under there himself with a ratchet and a wrench and have them both yanked in no time.

It is a very simple system and very reliable, that is why Subaru's are one of the best all wheel drive vehicles.
while I agree they are both simple and reliable I believe they are missing a huge link in efficiency, Subies have always been little piggies for this reason, When it comes to efficiency they are one of the most archaic drivetrains on the market, One; their spinning their engine the wrong way, then it has to be re-converted. Two; All time all wheel drive is a mistake and most subies are manual transmissions which makes this even worse as components are not only running all the time (automatic or manual) with the manual they are actually doing constant battle for dominance --- this in turn wastes energies in the form of working a viscous coupling -- What a constant price to pay in economy - when most all the time the cars are driven on dry pavement be it on a trip or to the shopping market. I cant imagine taking off for a 3,000 mile trip in the summer with a subie, it would literally sicken me.
If the cost of fuel keeps rising subaru will have to re-tool to keep up -- be it their front or their rear drive, they have to convert 90 degree's and utilize thick hypoid dope in both diffs, I have an 87 toyota camry sitting out in my driveway,(just threw a timing belt at it --- 316,000) it used to be my car -- its got a little 2.0 liter in it, Iv pulled over 42 mpg with it on long flat trips (and not "pampering" it) The reason -- At least when it comes to this car Toyota had their act together in just about every way, the engine is transverse mounted -- because they dont have to convert and use bevel hypoid gears they run a helical ring and pinon, They took advantage of this fact and upped the grade quality of all the trans components and went a class higher quality in bearings -- they did this for one reason and one reason only --- they get to use ATF (instead of 90wt) in a manual trans -- for ring and pinon and everything, Over the life of this ride this effort has not only saved the owner much money that otherwise would have been thrown away, its probably saved a small swimming pool of gasoline:) ----- there thinking -- I like that - Subaru skips this step...
This car has also gotten me through many of snow storm and with good tires was actually a tractor, (I live in colorado) but -- if Its an absolute must to have a 4wd in a car The design should go somewhat like this; Transverse mounted engine up front/w/transmission, typical front wheel primary drive system that either uses 10w40 engine oil (honda) or ATF (toyota) Extend final drive though case (with internal seal) to manual (lever or electric solenoid) actuated small diff filled with horsepower gobbling 90 wt.:p Run prop shaft back to rear diff with horse power eating 90 wt. -------- auto locking or manual hubs on the REAR wheels, although theres still two conversions its only when in 4WD - as it should be, The rest of the time you have a thinking mans drivetrain pulling you around (99% of the time)
Only price to pay is a couple hundred extra pounds (think of aunt Edna riding in the trunk ------ but at least the old gals not dragging her feet on the pavement;) )

For the record, personally I dont think this is the thinking that should be adopted for just 4wd cars, since most pickups are driving around empty spinning there rear wheels all the time i believe this strategy should be adopted for them also, put the power where the weight is -- and get more direct with it, theres enough room under that massive hood to mount a cummins 6 banger sideways, if not make it a V...


BTW, I am a Subaru Master tech and have worked on Subaru's on and off since the mid 80's, I am also an A.S.E. Master tech, A.S.E. Master Engine Machinist, Hyundai Master Tech, Toyota certified and Mazda certified. I got out of it in 2005 when I moved to Whidbey Island to open my machine shop. But about 6 months ago I started working part time at a local import repair shop. They were having trouble finding a tech so I told them I would help them out until my new shop building was completed.

If you need any help or import repair specs let me know.

Thanks Mark, I remember your info on the headgaskets was right on the money ( I still took a risk re-using that "out of spec" engine block --- still holding -- but fingers are still crossed, not sweating it as much cuz its way out of its warranty range and in fact theve already got much of their use out of it)

PackardV8
05-26-2008, 12:46 PM
We are preaching to the lunatic-fringe choir here, but agree with all the above:
1. 4WD is a huge waster of fuel. (BTW, whining, "Well, I live two miles off the road, so I have to have two 4WDs", and then bitching about fuel costs gets no pity points. Making the choice to live far out and far off costs in some ways, benefits in others. Shut up and deal with the consequences of one's decisions. The next one I don't want to hear again, "We have three kids, two big dogs and have to tow our boat, so I HAVE to drive this F350 Quad Cab." Make choices, pay the price and shut up about it.)
2. The most cost-efficient car is not owning one.
3. The second most cost-efficient is the one which is parked in the garage, not being driven on short trips. Simply by planning ahead, consolidating trips, car-pooling, I've improved my fuel economy by 25%.
4. In most local and national discussions, the agreement is, "We like the comfort of our mammoth 4WD SUVs; we like the convenience of every family member having a car; we like being able to jump in and run to the mall, the grocery for a single item, we like living in the far fringe suburbs. It's not fair we have to change anything. Just elect someone who will get fuel prices back below $3 a gallon and let's talk about something else."
5. This discussion, idiots rushing to give away big honkers for more fuel efficient vehicles happens ever few years. We went through this in 1974, 1977 and given the incredible stupidity of most US citizens, it'll be happening in 2074.

thnx, jack vines

Norman Atkinson
05-26-2008, 12:54 PM
I've just flown back to the UK- Newcastle(NCL) from Mahon, Menorca(MAH)
Been driving my little Hyundai 1.0 Getz- gasoline motor which is 2 years old and does way, way more than our Mercedes C270 CDI estate which gives well over 55mpg driven at English motorway speeds which are 70 mph and 60 mph on ordinary roads. My BMW 1.6 Mini Cooper gives 47 mpg in town- and I tend to thrash it.

There was an ad on a bill board for the 'new' High and Dry on a Mahon hoarding.
Now, I know the Diesel 1.5 whatsit does -------------------75 mpg.

Any comments about this newcomer? Or am I slaughtering more 'sacred cows'?

Mad Scientist
05-26-2008, 03:44 PM
If you want better mileage here are a bunch of ideas that you might try, They’re condensed from a site that is devoted to getting better mileage,.

If engine is apart, install put in new pistons to raise compression ratio to 9.5 or 10 to 1. This is known to improve efficiency, unfortunately it also promotes pinging with our cheep(?) gas so now you need to modify the cylinder heads with something called ‘Somender's Grooves” these are a shallow grove(s) cut into the squish area of the head, pointing towards the spark plug, they provide a better air fuel mix giving a more controlled burn thus no pinging.

Modify spark plugs by drilling a small hole in the ground terminal directly above the center electrode. This allows the flame front to advance from the end of the plug along with the sides.

As you are probably aware liquid gas does not burn, it can only burn if it is a vapor. Thus good vaporization of the gas is essential. To do this we need the following.

The addition of 2 ounces of acetone to every 10 gallons of gas. This reduces its surface tension and promotes better vaporization thus better mileage.

Wrap fuel line around radiator hose to pre-warm gas for better vaporization.

If the heads are off, cut thread like groves in the walls behind the intake valves. These help catch and hold raw gas giving it more time to vaporize.

Preheat the income air for better vaporizing of the fuel. Yes, yes I know everyone has always told you want cold air going into the engine, but that is for maximum power not maximum economy.

Oh and those vapor carburetors from the early 1900’s, forget about them, they do not work with our so called gasoline. Our “modern” gas contains too much oil which gunk’s them up in short order.

Place two strong magnets on fuel line (non-magnetic portion) with the south poles facing each other. OK this one sounds like voodoo magic, I can’t even begin to explain how it might work, but there are those that claimed it has helped.

Make sure brakes are not dragging, add 5-10 pounds of air to tires.

Cryogenically treat engine and power train. This reduces friction. (A client of mine did this to an older BMW, it went from 12 to 18 MPG.)

Make small “Brown’s gas” generator to supply HHO as an additive to the gas.
Many are getting good results with this.

Cover bottom of car with thin sheet metal (plastic?) to smooth out all the lumps and bumps making it more aerodynamic.

Reprogram the CPU or modify the output from the cars sensors (oxygen, etc) so that the computer with not “correct” for your fuel saving techniques by supplying the engine with more fuel thus voiding all your improvements.

Add napthalene (moth balls) to your gas; however do not just toss a bunch of math balls into your tank, because as they will not dissolve uniformly and they will clog filers and destroy fuel pumps. So first you will need to grind them up into a powder then add about six heaping teaspoonfuls to ten gallons of gas. This is kind of a stinky job, but at least you won’t be bothered my moths. Pour powder into gas tank and then add gas to cause it to mix. Car needs to have a modern OBD-II ignition system to automatically compensate for your new fuel, or you will have to manually advance the timing. Oh by the way remember when you are pulverizing the moth balls that they are toxic!

Please report back when you have broken the 100MPG barrier. :)

aostling
05-26-2008, 03:56 PM
Was just hoping it was bolted on the outer flange as well, Then Aostling could get under there himself with a ratchet and a wrench and have them both yanked in no time.

That I could do. I was just about ready to consult my Haynes manual when I read your post and learned that it is not so simple.

I have a 2500-mile round trip to San Francisco coming up. I'll stick to the high roads.

aboard_epsilon
05-26-2008, 04:13 PM
YOU FORGOT A BIGGY

Never use the heater in the warm up period ...
This can keep car from reaching running temperature...(depending how cold outside conditions are) by up to five miles or more......sometimes a ten mile trip in very cold conditions...if you have the heater on ...it still will not get to running temp.

so if you only do a five mile trip to work your car is constantly in fuel enrichment mode........and it's being prevented from reaching running temperature by use of the heater.

never let a car idle to warm it up ......

you're right about the warm incoming air thing ............may only Apply to old cars with carbs though .......as modern fuel injection compensates for air temperature .


blocking off the radiator in the winter will also speed warm up ......yes i know the thermostat supposed to do that ...but the effects of cold air blowing not through the radiator ...but over the engine block ...can slow down warm up.

if you are feeling really miserly ...
you can keep the oil a bit low in the winter .

also keep it garaged overnight .......

all the best.markj

A.K. Boomer
05-26-2008, 04:21 PM
Mad S --- some good tips, Iv pissed my bro off now and he's talking smack about the tercel, I left a bannana peel on his hood yesterday, The gloves are off -- its going to get serious now ( I even called it a "rust bucket" cuz its got the typical CRX rear wheel well rot), I need all the help I can get as his de-tuned little bugger is good right from the start, its got a de-tuned cam, roller rockers, long legs and its slippery,
I however just ordered an exhaust pyrometer kit and a mixture ratio gage,:D
Wish when I rebuilt her I had the foresite to go with ceramic coated pistons (its got a little layer of carbon on them, thattle have to due), but this is not my dream car and I never thought Id have it this long, just that everybody is hanging on to anything small now, not complaining as I coulda been stuck with a sloburbon, actually that would have been impossible as I never would have owned one:p

bobw53
05-29-2008, 06:32 PM
My 280Z is HLS30370415, it's an "early" 77 model. It has the JECS (Hitachi) clone of the Bosch L-Jetronic. It has EGR and a charcoal canister, but not much else. I seem to remember that I got about 16/20 MPG with it but it has a silly cam. I pulled the 4-speed and put in a 5-speed many years ago, since I had the R200 limited slip diff the driveshaft was the same. I bought the thing on April Fools Day in 1985, drove it for years, and now it's in my dad's garage since I don't have time or space to use it anymore. Someday I'll get to it, needs brakes on 4 wheels.

You got to love those cars. right now me and my business partner have 5 between the two of us, my rusted '75, a '76 that all my goodies are going into, a '70, just a rust free stripped body(thats got to be worth something), and 2 '72s, one a 10 year ongoing project with a small block and the other cobbled together that went to a grassroots motorsports competition a few years back, that car is light as hell and incredibly fast. There are several long black streaks through the center of the shop from that thing.

Here is a pic of the last mentioned car when we were moving into our new shop last September.

http://www.flickr.com/photos/bobw93/1424153882/

The 3 wheeler is hanging off of the crane, well, because we had a crane and we had to hang something off of it.

I really miss driving a Z, they are just fun, decent mileage, fast, handle like a dream with slight mods, I've fit a 318 dodge motor into the back of one, easy to work on, cheap parts. I've got to get that car going.

Oh yeah, there are a couple of blowers off of 3.8l GMs floating around here that will find their way on there before it all gets back together, so much for the mileage, though they do have a bypass on them, so at reasonable throttle, the mileage hit should be minimal.