[e90yyc]

Reviving this thread to chip in my 2 cents.

I’ve got an 07 328xi with over 200k miles that I changed the tranny fluid and filter on around 30k miles ago. Now, I know everyone with the 6L45 complains that it’s a piece of shit—they are not wrong—but I’m gonna flex a bit here and tell you all that my 6L45 is the shittiest of them all. It shifts like it’s filled with applesauce.

Anyway, due to still having some connections at my old work—flexin’ again here—I was able to get the genuine BMW Dex VI for cheap. You know what? Despite being a big fan of OE parts and fluids, I regret using it. If my transmission was trouble-free and smooth-shifting it likely wouldn’t have mattered, but because it’s in such rough shape, I really think a more viscous fluid like Maxlife would have helped.

I stumbled across a post on this same subject from a mechanic who delivered a pretty convincing argument against Dex VI. The crux was that the fluid was conceived with economy in mind and little else. As a result, it’s incredibly thin and only becomes thinner with shear (obvi).

I’m probably going to drain and refill with Maxlife or similar when the weather warms up. If I do this, I’ll be sure to post back with the results.