My 172 is on 104k. Had 2 new rear wheel bearings, on it's third exhaust (stainless this time). Second set of front discs. Still on original box and clutch and even original rear discs, although they're shagged. Still sounds and goes well. Apart from squeaky belt on a coldstart and noisy a/c compessor. Serviced regularly since I got it at 32k. Could last another 50k or go bang in 10 mins time! Wouldn't lose sleep over it.