For pre-purchase, Insist on seeing it start cold. That lets you know a lot. Things like is there condensation build up on the oil fill cap, What does the engine oil look like when cold, is there oil floating on the coolant in the radiator, how does it start when cold are there any cold engine knocks (not necessarily bearing noise). Then test drive it how does it respond, how does it shift, how does it stop. the rest is the same for any other used vehicle you might look at. After you buy it, change fluids, check brakes, and use the h*** out of it. It will be slow on the uptake, but if you give it enough time it will get up to speed and hold it just fine. Factory tires seem to get the best fuel mileage for me anyway When you start having problems that you can't figure out, ask here someone will give you the right answer. The only stupid question is the one you didn't ask.