The more I have been looking at pics of x's with really big wheels the more I am starting to dislike them!! I think the max I will go to will be 18's with a reasonable tyre still, I like the fact that it looks like a 4x4, and my end goal is to have something that still looks practically oem, with some added extras..the reason for the colour change is I haven't seen many, if any t30'sIncreased top speed is a myth as nobody ever gets to use it and I am not too sure how long I would want to be cruising at the limits of the cars engine and suspension.
My point was that the car was originally designed with 15 in rims which were then upsized on later versions first to 16'' and then 17''. 20'' rims is a fivefold upsize and I really dont think it will do anything positive to the vehicle. What is cool about an SUV that can no longer operate as such? Seems like a lot of money to spend on pure cosmetics, but that is me.
RE 17'' rims, I have used 215-60-17, 225-60-17 and 225-55-17. In comparison to the original set up size of 215-70-15, the first has a 1.1% diameter increase, the second a 3% diameter increase, and the last a .4% decrease. With the 225-60's the X is sluggish and handling at highway speeds is not what it should be. However with the 225-55, the car is zippier, and the auto transmission gearing seems to be bang on for it. Handling improves and it really feels planted at highway speeds. I can see why its a common tire size for the X in Germany where people actually get to drive at speed.