Save for a punctured tube while dismounting one of the tires for an experiment, I'm up to 1890 miles on my 700x30 Kenda Kwicks. Doubt I'll make it to 6000 miles (to say nothing of 20000!), but I think I've gotten my money's worth.
- Scott
P.S. This is the longest recorded mileage I have for any of the tires I've used so far...