Its royal purple that's in there now and its got less than 10000 miles on it. I have 1 bottle of oil left so I may change it all. A bottle of synthetic 75w 140 is 19 dollars a quart here. Of course that's royal purple but that's all I can find around here for some reason.
So if you have 1, then all you need is another 2 (rear ends take 2.5) I know its only got 10k on it, but if its gonna be open... might as well start fresh, rather than rechanging in 2 months, making another gasket, yada yada yada. just my pennies fallin out my head...
I'll admit, I never did it on my RWD cars, but its a fricken car. lol. Now Blue... she works harder than me almost. Whats recommended for your yr/model?