The carcas on the RA1 is pretty thick, so a slick tire can still last pretty long (one weekend for sure). The full treads just build up so much heat they start to chunk badly and that then overheats the carcass and the grip goes down, steering input goes up, and these tires don't like a bunch of slip angle. That's why AI cars, albeit a bit lighter, will see longer life than CMC guys, as they really have to slip the tire to get around the crappy OEM suspension (except the FOX's, as they have a superior suspension direct from Ford...).