What Race Oil do you trust?

[Alan Roehrich]

Originally Posted by Bob Gullett

I used to use the Joe Gibbs XP-1 5-20. Never again. Extreme sludge created by this oil pluging oil filters. Just about cost me an engine. Now I use 10-30 Valvoline race oil. No issues and runs clean.

The Joe Gibbs oil does not deal with blow by, fuel, or moisture very well, it forms a nasty gray gelatinous sludge, as you described. Uncontaminated, it does fine for us, we use XP-2. I'm not convinced it is all that fast, and I've never had bearing problems with other oils, so I can't say the Joe Gibbs is doing any better.

Insiders with NASCAR teams tell me the Joe Gibbs oil does not get along with some of the various coatings, especially some of the DLC coatings. Having a DLC coating failure is catastrophic.

We saw a measurable HP loss with Valvoline 10W-30 race oil, compared to the thickest Joe Gibbs break in oil.