Is it safe for me to use a Royal Purple product in my transmission? If so, should I go with the synchromax or another version of it? I read through the search button and it seems to be debated since GM recommends only their "special" transmission fluid. I have an 06 ss/sc. Can somebody please set me straight on the facts.

 

75w 90

 

I have BG snycro shift in mine, it is a lil bit better then what comes from gm.

 

does it meet gl-4?

 

Do a search! This has been gone over like 50 times in the last month! Royal Purple 75W-90 Max Gear oil! Its the only Royal purple product the meets the GL-4 requirement, has LSD additives, and also shockproof stuff in it. Phenominal product though!

 

21018899 saturn fluid from your gm dealer

 

The Royal Purple Max Gear oil is way better and still comes in about $2 cheaper per quart than the GM crap.

 

I went with the 75w-90. Seems a little smoother, but nothing major.