I don't know hard facts on when they need major overhauls... I mean, I know a guy right now that got one of these for like $200 with a blown up engine - I think he said it was spun bearings, due to that dreaded coolant+oil = bad that I mentioned earlier. It only had 70k or 80k on it. He's rebuilding it from the bottom up, but he builds drag race engines for a living, so it wasn't a big deal for him. So, YMMV, but they use these 4.3L V6's in the GM S-Trucks, Full-size trucks, Delivery vans, Marine, Power Generation, etc. http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/industrial/2010_4300_Industrial.pdf I mean, this single engine is pretty robust to handle all those duties. AWD system: I don't know the intricacies of that over the push-button 4WD on the other S-Trucks. My S-10 had an issue with the encoder motor that was replaced under warranty, but it serves the function of engaging/disengaging the transfer-case from the vacuum actuator - with an all-time AWD system, I don't know if you'd have that issue since it NEVER diengages. I don't think you'd have an issue with the transfer-case as long as you're not hotrodding it and cruising 85mph everywhere. The heat is what'll kill those. Fuel mileage. Ha! My last fuel stop I calculated 13.5MPG - Granted I only drive 2.5miles in city traffic to get to work. The best I ever got out of it, all-highway was 20mpg. I think you'll average around 15-16mpg assuming you keep your tires properly inflated and have a tailwind everywhere you go.