Heard all sorts of things about every brand of oil out there. Heard Quaker State and Penzoil both foam at high temps.
I own an 81 Malibu with over 500,000 miles on it, an 81 Buick regal with about 250,000 miles and a 49 Chevy half ton with 111,000 miles on it.
I have never touched or rebuilt any of the engines except valve stem seals on the Malibu. I use Quaker state 10W30 exclusively and change the truck every 1000 miles and the cars at every 3000 miles.
