Forget over 20k with your CF for tires... Not likely to happen. Expect 10-20K avg tire life. This is assuming OEM Z(W) tires. They are designed soft to grip and you cant have grip with tread wear. Which do you want- a car that is easy on the wallet- or a fun to drive, awesome looking car? If you wanted the easy on the wallet/no maintenance/cheapo tires then you purchased the wrong car!