Each pair of running sneakers I own is numbered and miles are logged to the 10th of a mile. I would say I am accurate within a 5% - I know this because at months end I square up my excel tracker and my garmin on-demand log. I rotate, I hand wash, I retire at about 400 miles. At retirement, they look awful.
I realized today that I don't have the same program with my trail shoes. I've had them for a few years, logged a fair amount of miles, regularly cleaned them with a pressure washer, and abused them to no end. They are still awesome looking, stiff, light, and even have the little nobbies on the end of the bigger nobbies.
Now, I really don't log THAT many trail miles but I do love it and plan on including 5-10 miles/ week this summer... So....Do I need new trail shoes?