[jc340]

I have 19inch stocks staggered on my xdrive 340

225/40/19
255/35/19

I live in the northeast and the low profile can be unforgiving at times. Was wondering what the max size tires i could run on xdrive sidewall wise while still keeping radial diameter the same?

[Billfitz]

Maximum size isn't what matters, maximum diameter is. You can check the diameter of the OEM sizes at tirerack.com. The smoothest ride and most resistance to tire and wheel road hazard damage comes with the largest aspect ratio number, say 45 or 50. You then see which width in that ratio comes closest to the OEM diameter. I wouldn't run staggered, what it does with RWD it doesn't do with AWD, but depending on your wheel widths you may be forced to.

[jc340]

It comes stock with a staggered wheels. Will look into the aspect ratio on tire rack. Thank you.