I'd like to get this settled once and for all. I have seen so many differing answers from people regarding this, so PLEASE, can someone who really knows give me an answer/explanation?

1. Do you need to use Friction Modifier if you are using Royal Purple SYNCHROMAX in your tranny?

2. If yes, what will happen if you don't use it?

3. If not, will it hurt anything or shift less smoothly if you use it?

Please don't just speculate,I need a solid answer. If you have used SYNCHROMAX with or without FM please let me know what you've experienced and also if you've tried other products and they are better or worse.

Thanks everyone!

the synchromax already has the FM in the blend, so NO you do not need to use a FM with the royal purple...

synchromax is made for manual tranny's that need automatic transmmission fluid, because of the LSD....