Nigel

I'm getting close to my next oil change, and I've been trying to figure out which oil is best to use. I've been looking at the Mobile-1 0W-20 oil, which claims to increase fuel efficiency while providing more than adequate engine protection. I've also been looking at Royal Purple's 5W-20 oil because many people have told me that RP oil is great.

So which should I use in my next oil change? The Jeep has 19k miles on it, and I live in southern Ohio, which gets pretty warm in the summer (70-90 degrees) and somewhat cold in the winter (0-30 degrees.) If it really helps, I'd like to use the Mobile-1 0W-20, but if there isn't much of a difference between that and RP 5W-20, maybe I should go with the RP.

What do you think? Has anybody used the 0W-20? Has it helped fuel economy at all? What about RP? Is there a chance that it would help increase gas mileage? I'm currently using a 5W-20 blend, so maybe switching to synthetic will help no matter which oil I use...

Jiblet

Since we are heading into summer time, I don't see using a 0w oil as an improvement over a 5w.
Maybe in the winter time but we really don't see the low temps our friends WAY up north see. You live in prime 5w-20 territory. Not too hot not too cold.

The difference is going to be in the additive package not the actual oil so I wouldn't bother.

I think you would see a bigger difference in mileage by keeping your tires properly inflate and taking it easy on the skinny pedal.

Just my two-cents!!