FDNYBullitt

I voted YES because I know it does. We have tested it more than once on the Dyno and it averaged out between 4-7 HP, one was 9 HP but it may have been a fluke. Its not something you'll feel by SOTP but when your looking for every bit you can get out of it then its worth it, good luck.

Sxynerd

Whatever!

Colorado_Mustang

Wrongo, buddy. Synthetic does not come from the ground, which is why it's called synthetic.

Synthetic oil is manufactured to have molecules of the same size which increases in lubricating abilities while resisting boil-off and gelling.

All oils have additive packages, and some dino oils even have additive packs similar to the synthetics. The difference is the oil itself.

And, yes, synthetic oil will gain some power. As stated previously, however, the amount of power is low, but will vary from engine to engine based on clearances and the number of bearings/bushings in the engine.

From personal experience, a '91 Explorer 2wd/5-spd gained 2mpg (16 to 18) with just a switch to synthetic at 130k miles. No leaks, no problems.

AJ06GT

It just requires a little common sense really. Synthetic oil flows better, that we know. So if you have leaks, it will likely leak more. Under the same principle, if you have places that are just barely not leaking with normal oil, then synthetic may leak. It's not, however, going to make your engine start dumping oil everywhere. If your car is leaking already, I probably wouldn't change it. If your car isn't leaking oil at all, then go for it. I just changed my car over at 79,200 and it still doesn't leak a drop, nor do I expect it to.