Just wondering if anyone knows which weight to use on the transmission for a S5 NA manual transmission. I read on the haynes manual and it said 80w-90 but i was curious if you can run 75w-90 because my brother gave me two royal purple quarts for free. Let me know thanks

 

80W-90 & 75W-90 are basically the same. The 80W-90 just has fewer polymer additives. Effective weight of each, at operating temp is 90.

 

sweet deal thanks dude