9. Get a Tune-up
Making sure your engine is running as efficiently as possible will go a long way to the life of it and improving fuel economy. Aside from a clean air filter, make sure all aspects of your engine are running smoothly and have been replaced when needed, such as spark plugs, coils, distributor and the rest of your ignition system. Regular oil changes and proper oil and coolant levels will also ensure your engine is running properly. If your vehicle is overdue for a tune-up, get it done because it could also impact your fuel economy.

10. Gearing
We off-roaders often look at re-gearing our rigs to accommodate larger tires, but many times people will get so concerned with installing larger tires they will simply overlook re-gearing their rig to complement the new setup. Stock gears are designed to work with the stock tire size. It’s true that reducing engine revolutions at speed can potentially be beneficial, but if your vehicle is struggling or working harder to move the larger tires you’ve installed it can negatively impact mileage.