How can a semi tractor hauling 70000 lbs get 7 miles to the gallon of fuel?

A semi tractor hauling 70,000 lbs can achieve 7 miles per gallon by utilizing several factors: efficient engine design, aerodynamic features, and proper weight distribution. Modern diesel engines are optimized for fuel efficiency, and the use of advanced transmission systems can help in maintaining optimal RPMs. Additionally, driving techniques such as maintaining steady speeds and minimizing idling can contribute to better fuel economy. Lastly, tire pressure and maintenance also play a crucial role in reducing rolling resistance and improving overall efficiency.