A lot of drivers believe things about gas mileage that aren't true, because they learned from their parents when cars were much different. Here's a list of ten gas mileage facts that have been turned into MYTHS by new technologies.
1. You need a small car to get good mileage. Not true anymore. New technologies are making midsize cars a lot more efficient. This year, about half of the top ten most fuel-efficient cars are midsize or larger . . . NOT including electrics and plug-in hybrids.
2. Manual transmissions get better fuel economy. Automatic transmissions have improved a lot over the years. These days they do just as well or better than a standard transmission on the same car.
3. It takes more fuel to start up a car than it does to let it idle. Fuel injection means modern car engines start much more efficiently. Manufacturers recommend that you shut off the engine whenever you're stopped, except when you're in traffic.
4. An engine needs to warm up before the car is driven. Engines are much different now. You shouldn't push a car too hard until the engine is warm, but it doesn't hurt the engine to drive it right away. Plus, driving it is the best way to get it warm.
5. Fuel economy decreases as a car gets older. Not if you take care of it. A well-maintained car will keep getting the same mileage even 15 years old and beyond.
6. A new air filter gives you better gas mileage. Newer cars have computers that automatically adjust the fuel-air ratio. So a dirty air filter doesn't decrease your mileage . . . although it hurts your engine's performance in other ways.
7. You can use aftermarket additives to improve fuel economy. Studies show that additives don't make a difference . . . and they could actually damage your engine, or increase your car's emissions.
8. Premium fuel gives you better mileage. Only if your car was specifically designed for it. There might also be special conditions where it would make a difference, like if you're towing something. But the owner's manual should tell you about those.
9. EPA fuel economy estimates are a guarantee of the mileage you'll get. Actually, they really are just estimates. Lots of other factors can affect your actual mileage, including your driving style and the roads and conditions where you usually drive.
10. All vehicles are tested for fuel economy. It's actually only vehicles under 8,500 pounds. So the larger pickups like the Ford F250 and the Dodge 2500 don't have official fuel economy ratings.