Our '04 X has the V10 and 182,000 miles, the last 50,000 almost all towing an 8500 lb TT. I have replaced the brakes a couple times and the alt want at about 140,000. I think I will have to replace the ball joints before we take off this fall. The only thing I did to the running gear is tighten the steering box. I changed the trans filter once and I changed the plugs at about 130.000. It has 3.73 gears and works just fine. I like to run about 70 on the highway, if I go 60 it doesn't stay in overdrive quit as well. In the mou gains it will do 70 in 2nd gear at about 4700 RPM as I remember so even with the high geared rear end it will stay with traffic.