I just put a Ford Racing Gt-40 345 Horse Power Crate Engine in my 93 Gt Mustang. My car
is street legal, not a daily driver, mainly used for drag racing and some once and while street driving.
I know everyone likes synthetics, Mobil 1 especially. But when you race , you should change your oil very often. This could get quite expensive if you where to use synthetics!!! And I do change my oil every 10-20 rounds.
On my old 302, that had 126,000 miles on it, I used Valvoline 10w-40 Max-Life non synthetic with Lucas Oil oil stabilzer. 3-1/2 qts. Valvoline to 1- qt Lucas. That combo seemed to work great. The Lucas Oil stabilizer seemed to keeep the oil from breaking down as fast.
Ford Racing said to run 10w-30 for the 500 mile break in period to let the rings seat. I asked what to run after that and I told them that I'd be drag racing and they said 10w-30. I asked synthetic or mineral. They said mineral. My mechanic who is a former mustang racer and current engine builder for 30 years said he like a heavier weight mineral oil like 10w-40 in brands Amalie, Valvoline. He use to run 20w-50 in his cars
, but he wouldn't go that heavy for this motor.
What do you guys think? It's a new engine and I just want to run what is best.
I have e-mailed Valvoline, Lucas Oil, Castrol, and Amalie with this question. I'll post their replys when i get them.