There are several reasons for poor fuel ratios: - Driving habits. If you often press the gas pedal aggressively, that will take a large sip from the tank. Often driving in traffic jam conditions with lots of idling will also raise fuel consumption - Irregular maintenance. If you don't change the filters and fluids on time, that will impact the fuel mileage. Also, the engine and the fuel system need to be completely maintained to get the best fuel efficiency - Using cheap fuel. Always try to buy high-quality fuel. It will not only save the truck's components but also save money on fuel in the long run. There is also an option to buy fuel additive and add it yourself.