Synthetics are best

[Clay Thompson]

Whether it is Royal Purple or Amsoil, synthetics are superior in reducing friction. Unless you are racing and trying to alter the "grip" characteristics to improve your racing times use what the factory recommends Dextron III or equivelants. GM spent millions in R&D to reach that determination.

I would agree that if you change oil often the cheaper oils are OK, I do not.

I've measured gas mileage improvements from synthetics and I've seen less temperature elevation in a one-mile run with synthetics. I also use Amsoil in all my cars and have had good long term results--since 1990.

Compared to the price of a full-blown PTS upgrade for the best available 2004R technology on the planet, seems like low-cost insurance.

What does every top NASCAR team use?

 

[jakeshoe]

Hmm,
Never seen a Nascar team run an auto trans....

 

[2quiktocare]

Never have seen one run without synthetic fluid in it either.

 

[Clay Thompson]

Synthetic

Sorry for the-less-than-precise explanation.

Total synthetic lubricating fluids are what NASCAR teams run.

Smoky Y. started the trend of using synthetic oil by using oil that was used exclusively in jet engines at the time.

I've been told, but do not know this for a fact that, that autotrannie fluid is run in the NASCAR manual gear boxes--came from a reliable source, though.

I've used synthetic ATF in my Muncie four speed for over a decade--Amsoil ATF synthetic that is--went from rebuilds every three to four years to none! Also, shifts MUCH better. Also, used Amsoil ATF in a 3.0 Bimmer manual trannie, great results.

Synthetics have been the one consistently good and reliable things related to my automotive experience. The other is the use of ceramic coatings and the latest one I'm looking at is cryogenics--also used by top NASCAR teams.

 

[chevyII]

IM not 100% about nascar but in factory vehicles if the manual trans case is cast its 90W if the case is aluminum its ATF. All cars run a jerico trans and have magniesum cases.