I am going to be installing an ATI ProCharger on my 2006 Mustang GT. Would it be ok to run 5W30 while the engine is stock? What about when it's super-charged? Would it be better to stick with the 5W20 from the owners manual? What about 10W40? Thanks for your input.

Jon

:drive:

 

I decided to go with Royal Purple 5w30.

Jon

 

Good choice....when you are pushing the limits of your stock engine synthetic is the way to go...

 

The way I understand it is that you don't want to go to a heavier oil, because the tollerances are so tight on these engines, and you may not get adequate oiling in the heads.... I was told one time that 10W40 would leave them dry.... anyone else have anything to say that would clear this up?
and as for supercharged motors.... I can't speak to that.

 

Am I being silly asking why you'd want to change? Why would you want to go with a thicker oil in a new engine?

I don't have a s197, but I use AMSOIL 5w20 in my Mach.

 

I chose the operating temp weight of 30 vs 20 because I expect that a supercharged engine will run at a higher temperature than the normal engine. In Western Colorado we see temps ranging from 0 F in the winter to 100 F in the summer.

See also:

Engine Oil Debate