Best tires on BMW X3......
 

I want to change my 17" rims and 235/55 tires with 19" rims with tires and i want your opinion about that.
A dealer from Germany suggest Continental ContiSportContact 3 and
Dunlop for 19" rims.What you think about this?
Also i want to have 235/50 front and 255/45 rear tires and the rims are
19" 8.5 and 9.5.
Thanks!

Both are good.

One issue with the tire size: If you plan to go 19" the sidewalls will be likely thinner than what you want them to be. If you go 19" staggered, the size will be:

F: P235/45R19 R: P255/40R19

I'm having trouble guessing what model the Dunlops will be, because Tirerack does not show any available for the front tire size. For the rear, I'm guessing you'll go with the Dunlop SP9000 summer tires. I'd go with the Conti's.

I just did an upgrade from 17" to 18", which is more conservative, but easier to find tires for. So far, the ride has actually improved somewhat, probably due to a handful of factors.

Is it possible to put a 235/55 tire size on a 18" ///M rims of my X3?

I just bought a set of 18" BF Goodrich g-force TA for the x3. So far I've been impressed. Some reviewers claimed they were noisy but all were on cars and in different sizes. From what I can tell they are very similiar in noise level to the Pirellis that were stock but seem to stick a little better. Hopefully these will last a little longer than the OEM set. They had 26K on them and could have gone a little longer.