had them for about 4 years now but I am afraid they don't have much life left. I bought wider rear wheels a couple years ago and changed my rears with the FK-452's and I am not happy with them. They do okay for traction if it is REALLY warm outside but otherwise they don't grip very well. My rears used to be 245's when I had the 451's and now my rears are 295's with the 452's and I think the 451's still hooked up better even though they were 2 inches more narrow.
If anyone knows of a tire similar to the 451's, please let me know. Tread wear is less important to me than grip.