Fuel economy is calculated by the miles per gallon (mpg) or kilometers per liter (km/l) of fuel that a vehicle consumes. The more distance per tank of fuel, the better the fuel economy.
Through the 1950s and 1960s in the United States, fuel was relatively cheap and gasoline engines were not very fuel-efficient. This trend gave way to smaller imported cars in the 1970s, particularly after the gasoline shortage in 1976 when gasoline prices started their uphill climb. Today, consumers are struck not only by the exorbitant prices at the pump but also by a threatened shortage of fossil fuels. Combine this with continued unrest in the Middle East and it's easy to see why fuel economy has become a central issue to consumers.
Through the years, many engine designs have attempted to improve fuel economy without sacrificing power. Today's hybrid vehicles are the most recent example. Hybrids compliment a gasoline engine with battery power for use in city driving, where speeds are not excessive and frequent stops-and-starts are a major cause of poor fuel economy. When the driver hits the highway, the engine switches from battery power to standard gasoline power. Hence, hybrids use fuel more economically in the city than on the highway.
Regardless of the type of vehicle being driven, there are some things every driver can do to improve fuel economy. Experts recommend driving in a controlled manner at the speed limit, avoiding sudden starts and stops. Build momentum easily from a green light, and coast to stops.
Extra weight in the car also cuts down on fuel efficiency. Many people carry golf clubs or other heavy items in the trunk for no reason, or use the rear seat as a storage area. When vacationing, try to carry everything inside the vehicle rather than using a roof rack. Roof racks create wind resistance that reduces fuel economy.
Regular maintenance of a car also improves fuel economy. Be sure tires are inflated to the correct pounds per square inch (PSI). The steering wheel should not pull to the left or right when driving on a flat, straight road. If constant pressure is required on the steering wheel to keep the vehicle moving straight ahead, it likely needs a front-end alignment. Both issues impact fuel efficiency by creating added resistance against the pavement. The engine should also be tuned and running properly.
Gasoline expands in heat, so to get your money's worth, try to purchase fuel during the coolest part of the day. For those in warm climates, this might mean a visit to the pump early in the morning after the underground tanks have had a chance to cool overnight. Also try to combine short trips, as the engine runs more efficiently when warm. If you'll be idling one minute or longer in a standard gasoline powered vehicle, cut the engine. This saves money at railroad crossings, when chatting out the window, or when picking up passengers.