My belts last a long time... I usually set em to the loosest possible as someone said earlier... But I try to watch out so it doesnt skip from being too loose. I always check the tension before racing... I like to stay on the loose side, but remember that extreme loose is also bad... One of the major factors in having a long life is having your car clean... Debris can really mess up a belt no matter what type it is... Hope this helps...