BUZZLEE

which is better to use for fluid redline or amsoil royal purple

MikeyB

For which transmission??

MikeyB

big red psd cc

If it for the auto, just be sure it ATF+4 rated. Don't use ATF+3 in a 48re.

Locomotion

Amsoil & Royal Purple are different companies.

I used Amsoil Universal Synthetic in my '92 diesel always towing and had no problems at all. I plan on using it again in my 2004.5 when it comes time for its first trans. service.

You can get more info and sources here:

Amsoil info and sources.