Originally Posted by JBasham
Maxxis has a 155/70R18 for the same price as the 135. The diameter will be a tad larger but not much and should be closer to spec with the stock rear. I've ordered one and will give it a try on the BMW X5 steel rim from Tisher's.
This Maxxis worked out well. As a 155, there's a smidge more rubber on the road, and the tire mounts on the rim quite well.
I measured the circumference mounted on the steel rim, and it is the same as the new rear Michellin PS2s that came mounted stock on my ZCP.