Originally Posted by apkano
Tread pattern only matters cosmetically, more importantly....the sizes are the same.
I'd be more worried about that "r" rated tire. The "z" rating is correct for Crossfires. I wouldn't be doing any 150 MPH runs with tires that aren't rated for those speeds.
"r" rated tires are good up to around 106 mph.
http://www.tirerack.com/tires/tirete....jsp?techid=35
Check out the page you linked a bit closer.
The R in the tire size is not the speed rating, it's for radius.
Each of the tires he is looking at on his car are W rated (see the 92W after the size), which means they're good to 168mph (higher than Z). For some reason, some tires put the Z in the tire size too...which means they're Z
or better...you have to look at the service description (the 92W in this case, to see if/how much better than Z)...from the tirerack page:
"While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed."
I'd rather have identical tires, but these are so close to one another that I wouldn't sweat it. (assuming they're both close to new...I wouldn't want one brand new and one at the end of it's treadlife.)