Hi Matt, As your motor gets older fatigue will take it's toll on engine parts. So if your talking a 350 RWKW tune then there will come a time to start de-tuning the engine. The good thing so far is we are seeing more and more 100k plus vehicle still happily pushing out 300+ at the wheels. But the standard rule applies, treat your motor well and it will last a long time, flog the living SH#T out of it and it will cost you. My car has a motor with only 39,000 on it but the driveline and the rest of the car has around 109,000 k's on it. I had the auto checkout a few weeks ago and everything is running well. I sold my old motor which had 98,000K's on it and it is now in a mates car pushing out 387RWKW's and loving it. One of the things people don't like doing is spending money. But remember the better the bolton's you buy the easier it is on your motor.eg Stall Convertor, Induction Kit, Actuator and exhaust ............ A must is good OIL and a friction modifier I use Nulon's E20. If you are giving your car a hard time change the oil every 5,000. I hope this answers your question in a round about way. TK