I know that if there is too great of mis-match between the diameter of the front and rear tires, the traction control will intervene. I had this happen once on M3, as the fronts were too tall, and the system saw the rears spinning faster, and would cut throttle. So my question is: How fussy is the E55.

Can a person run a 255 front with a 285 rear. In looking, the sizes are

255/30/20 will be 26.1" in diameter. 797 revs per mile
The 285/25/20 will be 25.6" in diameter 812 revs per mile

So the differece is only 15 reveloutions per mile...
Is that enough to engage the tractiona control? Anyone using this sizing?

Thanks!!!!

Why not run a 245/30_20 in front? It's only 25.8" in diameter and only 0.1" taller than stock. The system would definitely not have a problem with this sizing.

Are you trying to run a 255 in front for a slightly larger contact patch?

The user in this instance is getting new tires with a set of wheels. 255/30-20 are on the front

He will need to buy rears as the tires coming with the wheels will not fit on rear. The goal here is to buy only 2 new tires if possible.

thanks!

Sizing seems to be spot on for a 8.5-9" up front and 10-10.5 out back. Looks pretty good to me.

Makes sense. I can relate to only wanting to buy 2 new tires instead of 4.

I don't see a proble with the size difference. My rear tires are .8" taller than the front in overall diameter and I don't have any issues with traction control engaging.

P.S. Don't confuse the above statement with my current steering angle sensor problem. That doesn't apply here.