Have 1250 miles on the 109 in just over three weeks.....no hard burnouts.....some inter-state miles but mostly twisty riding......center is starting to flatten but no major difference in cornering......at this rate 4500 to 5000 mi. might be tops for this tire. Already have a new 250/40-R18 Dunnie on the way just in case I reach "Dead Carcass Stage" with the present tire.