I have a 99 E350 with 380k. It averages about 20, with a range of 17 to 23 depending on speed, wind, ect. Under 70 is better than over 70. I've had no tranny problems with twice yearly service. 1 alternator, 2water pumps ($450 for the pump+labor), front brake rotors(they warped and they are very expensive), 4 front wheel bearings, rear end twice(but the first time was when the first wheel bearing went at about 28000. I was sure it was a bearing, but dealer said it rear end, but that's a whole other story.),1 injector at about 120k. That's what I can think of off the top of my head. Some people would run nothing but a diesel, others wouldn't touch them. I know a guy who has a 94 Ford gas with about 800k and he put in his first tranny about 6 months ago. He never idles, but lots of gas guys idle all the time.What will I chose next time? Right now I just don't know. All the best!Highway Star