For those of you using synthetic fluids

[kelleyperformance]

for all using syn fluids such as amsoil, royal purple, or mobile 1- a slight improvement is felt by switching from dextron III to a synthetic fluid. however, when i switched mine, i not only noticed no drop in operating temperature, but my shifts became weaker (stock and with shift kit). so i put dextron III back in, and it got even sloppier. months later, i saw a box of dextron VI. i had no idea there was a VI, i thought i was reading it wrong. turns out it recently came out and is in late model 06 and all 07 65e's and larger. thats what i originally had, and i can tell you as a performance nut and a mechanic that it is FAR better than synthetic, and cheaper. i just changed my royal purple to the dex VI when i put the yank in, and wow..... MUCH smoother shifts and lower temps.

 

so anybody not running it, GET TO IT!!!!

[brobradh77]

thats what I run in mine and I like it but I have not run any synthetics except for my motor oil.

[wkdivr]

I was under the impression that Dexron VI is the official GM factory synthetic fluid.

[CoolBlueSS]

Dexron VI is replacing Dexron III. Don't know what happened to IV and V. You can use VI in transmissions that take III, but not the other way around.

[faceliftedss]

thats what i'm going with

[12'SROCK]

WTF! so any one with an 06' needs to run dextron VI not III? isnt the transmission the same for all the SSS 4L65E?!

[CoolBlueSS]

The only one that I know of that requires VI is the Allison 6 speed auto, and all 2007 models. But, Dexron VI will eventually replace III.

[12'SROCK]

Thats what i was thinking, you could run III or VI in the trans because nothing has changed internally its still the same thing.

[kelleyperformance]

dextron VI is just a replacement for III that is 100% improvement in all aspects or more (i have the specs somewhere arround here). its not necesarily required in our trucks, but GM recomends it and it came in all vehicles as of late 06 and forward. however, the 6L85e in the corvette, the version of that in the 07 escalade and denalis, the allison, and the 5-speeds in the V6 cars require it. they will all run III, but its not a very good idea. it will kill the lifespan on the trans.

[nixsupersport]

i run amsoil syn. in my front rear diffs, and gm blue shit in the transfer case, and syn. amsoil in motor 5w30.......did you know that the transmissions are 4l60e's or are some 60's and some 65's

[TruckinSS05]

thats what I run in mine and I like it but I have not run any synthetics except for my motor oil.

 

Same here. I have not run any type of synthetic execpt in my motor oil as well. Along with a K&N oil filter of course!!