SAN FRANCISCO (4/15/14)--Choosing a fuel-efficient vehicle, maintaining it, and combining trips will help you get good gas mileage. Other efforts could be just a waste of your time (MarketWatch.com March 29).
There are lots of fuel-economy myths and overstatements, but here's the truth, according to fuelconomy.gov:
Myth: All vehicles are tested for fuel economy. Current fuel-economy testing regulations only require "light-duty" vehicles weighing 8,500 pounds or less to be tested. Several models exceed this limit and aren't tested and have no official weight limit. Passenger vehicles--vans and SUVs--that are model year 2011 and newer weighing up to 10,000 pounds also are required to have fuel-economy labels. The Environmental Protection Agency doesn't test motorcycles, or four-wheel vehicles that aren't legal for highway driving.
Myth: Small cars always get the best fuel economy. About half of the top 10 most fuel-efficient vehicles for model year 2014 are midsize or large cars and wagons. Technologies such as diesel engines, direct fuel injections, hybrid drivetrains, low-rolling tires and aerodynamic design make several standard-size autos very efficient.
Myth: As cars get older, fuel economy decreases. If you properly maintain your vehicle it will retain its fuel efficiency for years. Fuel economy typically improves over the first several years of ownership. Even vehicles that are 10 to 15 years old experience little decrease in fuel efficiency if properly maintained.
Myth: Using premium fuel improves efficiency. Unless your vehicle is specifically designed for premium fuel, you most likely won't receive a benefit from using premium fuel. Check your owner's manual to see if premium is recommended for your vehicle and under what conditions.
Myth: Replacing the air filter increases efficiency. This might be true for older vehicles, but modern engines have computers that automatically adjust the fuel-air ratio to the proper level. Changing a dirty air filter might, however, improve your engine's performance.
For related information, read "Find the Best Low-Cost, High-Value Car" in the Home & Family Finance Resource Center.