truck buying

What you should be looking for depends on you. What's important to you? Fuel mileage? Reliability? Easy access to service centers? Low cost? Big sleeper? Only you can answer these questions.

Mileage range depends on your budget. Your typical big truck will last 1 million miles+. Most will need an engine rebuild somewhere between 500K (end of warranty period) and 1 million.

I'm not aware of a carfax-type service for big trucks. My recommendation would be to ask to have the truck inspected, and possibly dynoed, at an independent diesel shop that YOU find (not the shop in the back of the dealership, and not the dealer's buddy that he refers you to). Some state DMVs have a web site where you can look up the status of a title and registration by VIN number, e.g. to find out if the truck has a salvage title or an unsatisfied lien.

If you tell us a little more about what you plan to use the truck for and what your priorities are, we may be able to help you better. It's a buyer's market out there right now, so you can get some incredible deals.