Have broken down motor with Quaker state oil in them and you are right sludge city. That is all my dad ran in his vehicles. Mobile one is a good one or like now running Rotella in my motor's. But now see that they have taken out the zinc in it. So, the oil wars continue. With like Synthetic oils. Still use a zinc additive when changing my oil in the 383.


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........ seriously though, this was 35 years ago; fresh 20/50 seemed good enough to me, figured they were all the same













