[Brian Edward]

BMW says not to rotate front to back/ back to front?...Anyone know why?

[Creynolds]

Originally Posted by Brian Edward

BMW says not to rotate front to back/ back to front?...Anyone know why?

Staggered bigger in the back then the front ?

[Surly73]

Originally Posted by Creynolds

Staggered bigger in the back then the front ?

If you have staggered that is absolutely true.

On square setup BMWs, it's been BMWs long time recommendation not to rotate because of stability problems caused by particular front and rear tire wear patterns. Remember, they're giving recommendations for their vehicles all over the world, including where driven >250kph.

I can say - I agree, and learned first hand. The rear ends usually have a fair bit of negative camber. Traditionally, sport package BMWs have also worn the outsides of the fronts in a distinct way too.

I DIY everything. In my E39 days I didn't drive a lot of miles and I had dedicated wheels and tires for winter and summer. I could rotate tires whenever I want. I decided originally (for years) to ignore BMW's recommendation since I could rotate them so often. I would probably rotate half way through each season, probably around 3000km (1800mile).

Now, my sport package E39 communicated the road condition very well. I kept the suspension tight, it had rack and pinion steering, and I was very in tune with what was going on with that vehicle. On my summer tires (Toyo T1R or Michelin PS2) I felt like I was always chasing mid-corner stability issues, thinking it was loose balljoints that needed repair etc... One afternoon I rotated the tires front/rear and went out for a drive. I realized in aggressive corners that the stability had returned and even turn in was quicker. It was like I replaced some components and got an alignment! I kept extensive records in spreadsheet and I dug back through them. I found that I had just returned the tires to the original installation locations.

So, even though I rotated every 2000 miles, I still observed issues. I'm not sure that the F10 chassis communicates nearly well enough to pick up on the differences, but I stopped rotating after that. On my last set of summers before my E39 was totaled, I let the rears wear down and replaced just the pair of rears. No more weird handling.

I also had a situation with my E90. I swapped front/rear because I wanted to try to get another season out of the set of 4 leading up to selling it. Same deal - squirrely handling encountering pavement contours mid-corner. Put it all back where it belongs and it tightened right up.

So - I've seen it on E39 and E90 chassis myself. Always tight, sport package cars with top tier summer rubber.

[Brian Edward]

Great read, thanks!