Multi-viscosity motor oil question.

[A.K. Boomer]

It is if you knock all the sludge loose & it plugs up the oil pump pickup which I did on a '53 Dodge Dart that had run non detergent oil so I cleaned out the valve cover which was packed solid but couldn't get the pan off without pulling the engine so I put detergent oil, drove it home from auto shop,oil light came on, kept driving engine seized just as I got home.

penzoil's old "formula" killed many an engine - very high in paraffin

Got my start working on the old air cooled VW's and they and penzoil did not mix,
so many time's would go to do a valve adjustment - drop the covers and all kinds of layers of flaky scaly crud would fall out onto the floor, rocker arms not even recognizable --- would then ask the owner what they were running and 9 times out of 10 penz was the reply, the occasional quaker state was the other answer to the question, it was not a whole lot better,

Valvoline was superior that way - never a problem it's all we used...

nothings tests engine oil like an air cooled engine in my mountainous state...

I have had guys with tractors tell me penz is all they used and they never had a problem - that's fine - just don't run it in air cooled car engines going up mountain passes, your tractor is so underpowered and it's got water cooling is the answer to how you got by running an inferior engine oil...

that's back in the day - penz has evolved some...

[flylo]

I bet if you had a bad cylinder it was always #3. We used to build dune buggies by cutting 14" out of the pan. We built ones that would do wheelies but I don't remember how much we cut but they were a blast.

[A.K. Boomer]

Yeah #3 on the early ones due to the oil cooler being in direct path so 3 was getting "cooled" with super heated air in the first place... the result was usually gobbling up #3 exhaust valve when the head popped off and got munched by the piston,,, and people talk about german engineering like its some kind of a godsend --- more like a wet fart afterthought,

then they came out with the dogfoot oil cooler that had it's own discharge vent and they ran a 10% larger fan to make up for the lost air volume,

those engines held 2.7 us quarts of oil !!! and no oil filter! it is actually amazing that they did so well, if you got 100,000 miles out of a typical beatle engine you were doing quite well...