While I have two sets of tire for my 19" wheels I can decide what to send back? I have a set of 245/40/19 f and 275/35/19 r.
and a set of 245/35/19 f 285/30/19 r. the recommended size. The first set is almost 1 inch bigger, and it is not the rubbing possibility that bothers me as if this happens I could live with it.

THE PROBLEM IS - Will a 1 inch difference mess up the AWD? Can you increase the overall diameter without screwing up the AWD? Any expertise in this matter would be greatly appreciated.

Also looking for a strut bar for a 2008 535xi thanks

 

Use this tire size calculator to determine http://www.miata.net/garage/tirecalc.html the rolling radius for the tire sizes you've mentioned. I think the 245/40x19" will be too tall for the xi - especially since the 245/40x18 is the stock tire size for the sport/performance tire set up. And I'm sure a 1" difference in diameter ( front to back ) will likely raise heck with lots of things including ABS and Stability systems that measure differences in wheel rotation and slip. Then there's the issue of fit too!

 

Yes everything you mentioned is what I am concerned about, I know that the 40/19 is almost 1 inch taller. I just dont know if it affects abs or awd etc. As for fitting there is plentty of wheel well. Just dont want to take any chances with the systems.

Thanks

 

It will effect the speedo but i think if all 4 corners are near the same height you should be fine. I think it will raise your car up a bit, I would stick with the recommended sizes, keep it as close to stock tire height as possible.

 

Thanks