5. Tire Weight
It only makes sense that tire weight is tied to rolling resistance. Heavy tires take more power to get spinning and keep in motion. Simply put, the more power needed to keep a tire moving the worse the gas mileage.

Looking at the overall weight of a wheel and tire setup is an important consideration, as heavy wheels can be just as much to blame as a larger, heavier tire. Running the lightest tire and wheel combo possible will help to increase your MPG.

6. Vehicle Weight
Four-wheel drive vehicles are heavy by nature. Heavy axles, larger tires, transfer cases and heavy-duty frames all add pounds. Heavy items are just inherent on a 4×4, but vehicle owners are just as much to blame for adding weight when they purchase winches, bumpers and other items to carry tools and spares.

Before blindly adding that heavy-duty bumper to your Jeep JK or truck, think about the items you will need to carry and gauge what’s necessary and what’s not. Trimming down on unnecessary items will trim down on overall vehicle weight and help improve fuel economy.