250000 miles, used for towing horse & utility trailers and general ranch/farm work. Above average time in 4WD and on dirt roads. No major mechanical problems & still 100% reliable and gets about 21 MPG on the hwy. Pulling a gooseneck horse trailer, 12-15 MPG average. I perform my own maintenance & have replaced all fluids with Amsoil products; including an aux. oil filter. The motor has no leaks. I have replaced all hoses once and flush & replace the antifreeze every two years. Oil changes at 50K with the Amsoil aux filter. I replaced the seat last month & have had it repainted as the paint flaked off at 100K miles. The gears, clutch, and transmission are fine.
Power & hauling: The combination of the Cummins with the 3.5 gears and 5 speed make a perfect towing package. Manual 4WD as I can lock out the hubs and use low range for rough ground and backing trailers in tight places.