Never let it run hot, keep good oil in it plus changed regularly and you should see well above 100k. I worked at a lumber yard where we had a runner truck that above 200k on the I6 in it and it ran great. The only maintenance I ever saw performed was gas when running low. Oil changes? Not sure anyone even knew where the hood latch was, but it ran strong. Funny, the more grossly overloaded it was, the more you knew it was a tank. Like it ran better under heavy load. Most mechanics I've spoke with about i6 say the 2 reasons they faded away are they are never going to be a fuel efficient choice but more importantly they are too reliable for car makers taste. If they never get to sell you a new one or work on that one then that is bad for the bottom line.