The new low sulfur fuel is lacking in lubrication so adding oil to the fuel will make the injector pump last longer. Changing the differential to one with a lower numerical ratio like a 2.73 will increase fuel mileage and make the engine last longer by reducing the rpm it turns at highway speed.
Parking your big Blazer or pickup and driving a small economy car when you don't need to haul anything will make you Blazer or pickup last longer.