[B58 parts]

The 340i xdrive I have here [non track package] came with the 400M style wheels, 18" ... 225/45/18 on all fours.

225 is not near enough meat for this thing, it should be at least 245 from the factory ... track package or not. These will do ok for the winter, but I need to get a summer set of wheels and aren't really sure what my options are. My previous dinky little car even had 235s...

My confusion is mainly around a staggered setup. I think with the xdrive you can't really stagger as much due to the center diff / transfer case. Those of you that have the xdrive and went wider, what wheels do you run and what sizes are the tires?

I would also prefer to keep the exact same height as OEM as I don't want to throw the speedometer etc off.

I have no plans to ever change the suspension from stock so I don't think rubbing will be much of an issue. I'd prefer to stick on 18" wheels if possible, 19s look too big to me.. Ideally i'd be in the 255 area on all 4 with 18s. If I can go even wider in the back over the front, great. I'm just not really sure what people opt for, usually there's a go-to setup that everyone runs.

[.BMW.]

Wider 18" tires with diameter close to OEM would be either 245/40-18 or 255/40-18.

[7iM3less]

I stuck to oem specs with my 328i xDrive and both set-ups look fantastic.

400m square for winter - 225/45/18 square

403m staggered for summer - 225/40/19 front and 255/35/19 for rear.

[WallySlash]

245/40 R18 on 428x with stock 397 wheels.

255 rubbed in the front when making tight turns.

For potential speedometer issues check

https://tiresize.com/calculator/

[floydarogers]

Originally Posted by YuminNuman

...
My confusion is mainly around a staggered setup. I think with the xdrive you can't really stagger as much due to the center diff / transfer case.

You can use the same staggared set on an xDrive as on a RWD. The usual is 225/45R18 front, 255/40R18 rear. Granted, that leaves you with the same understeer you have now... If you can find them, you can go up by 10-20 mm both tires. But some sizes are simply not available.

[Pipe335i]

I have 403m staggered with 255/35r19 in all corners, no issues at all .f30 335i rwd