I am running dayco on all my sleds and love them they are very good with the one year waranty free replacement... the belt on my mountain mod 700 has 1200 miles on it, my mxz 700 has 600, and the formula 3 600 has 800 miles on those belts... Also another belt that I used to run was the NAPA belts they were very good but they are about 2x theprice of the dayco...