I am going to put on four 18x8.5 rims on my '07 525xi. (A picture of rim is attatched). I want to run all 255/40/18 tires all around. Would these fit on my car with no rubbing, etc., or would I have to go with a smaller 245/40/18 tire?? Anyone with a clue, please respond quickly! Thanks!

The wheel offset should be 35mm or higher (43mm is standard). If it's an OEM wheel the offset will be marked in side the wheel. The proper bore size (72.56mm) is also required or a hub adapter must be used.

The stock tire size for an 18" wheel on an e60 is 245/40x18.And since your car has TMPS you can transfer your sensors from the old wheels or buy new ones ($200-$400 / set) - installed they do not require any special coding ... only a reset done in iDrive.

Ok thanks for the reply. Do you think 255/40/18 rims would fit though?? Without rubbing. These rims are ET 35

The difference in overall dimensions are very small and the slightly larger tire should clear. You can use this tire size calculator to see the typical differences.

You also need to be cognizant of the speedometer error brought about when altering the rolling radius of the tires on your car ... With an xi be cautions about mixing tire sizes front to back - must maintain the same rolling radius to prevent the electronic stability and traction systems from getting confused http://www.miata.net/garage/tirecalc.html