Front: 20x9 with 255/35/20
Rear: 20x10.5 with 285/30/20

I belief offset is 18 for both

These are coming off an e60 m5 but not sure if they will fit on an '08 550i mtech. If so, will they rub. Will speedometer be off. tks

 

I am running 20" wheels, they are 9j et15 front and 10.5j et22 rear, i am running 245/35/20 and 255/35/20 although the rears will get changed to 265/35/20 due to the ammount of strech the 255 have and although it looks cool i am not 100%happy with it atm.

If they fit an M5 they should fit your car, as unlike the e39 where the rear wheel arch liner was different on the e39m5 and the e39 sport i think its all the same on the e60 model

 

No it's not the same. E60 M5 has wider front fenders, and the rear fenders are rolled. Sure you can get the rear fenders rolled, but to get the same room for front you have to change the fenders.

However, this doesn't mean that mentioned wheels by the OP wouldn't fit. I believe the wheels fit, but you may get some rubbing with those M5 sized tyres. The correct size for a non-M5 would be 245/30 R20 and 275(or 285)/25 R20. Running oversized rubbers is always a tough question, and many things will affect the result (rubbing or not rubbing). Those 255/35 and 285/30 may fit without any problems, or then they don't. If you can do a test fit, I recommend it.

- Antti -

 

I thought the size commonly used when going with 20's on a non-M was 245/35/20 and 275/35/20. If I have to go to the above I won't bother. Not enough rubber for a DD to keep the ride smooth enough. I didn't think the M size would work either. tks