If you plan to use your truck like a car, desiring quick, quiet acceleration and rarely ever haul a heavy load and don’t plan to it for a long time, you may want a gasoline engine. Gas engines run smoother, fuel is easier to find, and gas engines start easier in cold weather.
If you plan to use your truck for towing, value good fuel economy and plan to put plenty of miles on it, you may want a diesel. The price to buy a diesel truck is really high, although they can offer you a lot in return.