Gas mileage for a coach bus varies between 3 and 6 miles per gallon, depending on the amount of use, distance driven and fuel type. The mileage for coach buses designed to carry multiple passengers is often measured in person miles per gallon, which is based on the average number of passengers per vehicle and can be between 25 and 38 pmpg.
Coach buses are traditionally fueled with gas or diesel, but newer buses use biofuels or a combination of gas and other environmentally friendly fuel options like electric or natural gas. These vehicles can have a mileage as high as 9 mpg.
Transportation companies use average passenger load figures to suggest that traveling by bus is a more fuel efficient option than traveling by passenger vehicle, even if it is a hybrid. Their claim is that buses travel the same distance with more than 50 times the amount of people, which helps decrease greenhouse gases by lowering the numbers of cars on the road and reducing the use of fossil fuels. For example, the Southeastern Pennsylvania Transportation Authority (SEPTA) suggests that a full coach bus is six times more fuel efficient than the average passenger car.