Originally Posted by tlminh
How much oil are you guys putting in?
Also, odd question, If I put in 5 quarts of 5w30, and top off with 1/2 qt of 5w20, do I get 5w27?
It's OK to mix different weights of the same brand, but try to avoid mixing different brands, i.e. Pennzoil Platinum and Mobil-1 as different brands have different additive packages they add to their oils.
I've seen lots of good results from mixing Redline MT-90 and MTL in the gear oil of MTX FWD cars with open diffs...much better results than doing either alone. And I've mixed Mobil-1 0W-20 and 0W-30 on multiple occasions in my wife's Xterra and gotten good UOA results back with TBNs still being in acceptable ranges at 8000 mile oil change intervals.