Re: oil weight?
The lightest oil that gives you enough pressure.
I only use the green cap Mobil1 10W-30
I have over 20psi hot idle and more than 40 driving around part throttle.
That's in hot ass Florida, making over 500HP.
The big NASCAR and ProStock engine builders usually like RedLine or RoyalPurple, but I like buying my oil in 5qt jugs on sale at WalMart for $17.88. Plus, I change oil every 1k miles or so, so cheaper is better for me.BJ's wholesale is clearing their supply of the old Mobil1 for $18 a case of 6, FYI