High mile gas engine trucks

Most gas engines nowadays do not wear out. The rest of the vehicle has issues related to old age. If the vehicle dies because of engine problems likely it drivers fault. Back in the day, Dad bought a new car, knew that every time you put gas in it, you check all the fluid levels. Now, most hoods don't get lifted between oil changes, and everybody wants to go as long as they can between changes. A small leak, and the engine can bleed to death between oil changes. IMHO, the best thing you can do to extend the life of engine is put a locking gas cap on and solder the key to the dipstick.