Rusty S posted:I run my car with 20w-50 out here in the hottest summer months. I used to subscribe to the "don't run 20w-50" fear mongering. My car runs very cool in summer and I have the added confidence that the engine is well protected. In the colder months I switch to 10w-30. I use both Valvoline VR1 Racing and Amsoil Z-Rod in 20w-50 and 10w-30. Anyone who knows me is well aware that I am a fanatic about quality and good engineering. I am also a self proclaimed expert on vintage steering wheels and motor oil.
Me too....JPS recommended Valvoline 20/50 all year long and that is what I do (except I don't drive in the winter)... John says synthetics are not good for air cooled engines .. they have a 24/24 warranty on their engines so it makes sense to me that they are recommending what will protect them...