Redline 75w90 diff fluid...am I crazy?
 

Ok...am I crazy?

I spend 4 hours per weekday in my x3 and think I know her well after 102k miles.

Two weeks ago, I replaced the diff fluid with redline 75w90 (previous changes were with BMW fluid by dealer) and my automatic x3 seems to now be an absolute rocket ship off line. I have always had a "lag" when I hit the go pedal but now I don't...my wife even noticed.

Okay, once again...am I crazy? If I am not I highly recommend redline diff fluid!

Yeah, I actually noticed pretty much the same thing. Not exactly a rocket ship, but noticeably smoother and zippier. I changed it to Redline about a month ago and could tell immediately.

Also, temperatures have started to go down, more cold air in>>more HP out :). That and you usually stop using the a/c as well, which the compressor takes well over 5 hp from the engine.

Exact product I use in my Porsche gearbox. Redline makes a good product. Never noticed improved acceleration however.

Yeah I think is more of a "placebo" effect! :)

Lol...very well could be a placebo effect but it is extremely noticeable even after 3k miles.

Here's my theory:

The stickier fluid with extra additives is allowing the pinion gears to more freely spin. Therefor when power is applied it gives the feel in the drivers seat of improved acceleration because throttle lag has been reduced drastically. Sport mode heavy acceleration truly pushes you back in the seat now.

Like I said...that's my theory, so I could be wrong but it seems plausible. Either way, I am glad I made the fluid switch.

Yeah, same here.... It very well could have been a placebo effect, but it sure seemed smoother and zippier immediately after the change (I did the diffs and TC fluid at the same time. They'd never been changed until now @ 70k). Now of course I have no idea because I'm used to the feel again...

Either way I'm happy!