Improving Your Car’s Aerodynamics
A car’s physical shape makes a big impact on a car’s fuel-efficiency. Car’s that are built to be more aerodynamic have been engineered to cut down as much wind-resistance as possible, and in return fuel-efficiency increases.
So if you are car shopping with fuel-efficiency in mind, looking for a car with an aerodynamic body (Chevy Volt, Tesla Model S, or Toyota Prius are very aerodynamic) is a great place to start. But for those of us that already have cars, there are certain driving tips and car parts that can help improve your car’s aerodynamics.
Lighten your load
This first begins in car selection, the heavier a car is, the harder it is to push against wind resistance. So when car shopping, get the lightest vehicle that will still meet all of your needs. If you are searching for a truck for towing, one with a smaller cab can tow more because less weight is devoted to moving the body of the truck.
Second, don’t haul unnecessary weight around. An extra 100 pounds in your car can increase fuel consumption by 1–2%.
Windows Down or AC
When traveling at fast speeds on the highway, having the windows open will decrease fuel efficiency as it will make the car less aerodynamic, so the AC is the best choice. For city driving, using the windows to cool the car is a better option as it will cause the engine to work harder — this is especially important with hybrid and electric vehicles.
Don’t Put it on Top
Hauling cargo on your car’s roof increases wind resistance and lowers fuel economy.
According to fueleconomy.gov, large, roof-top cargo boxes can reduce fuel economy by around 2% to 8% in city driving, 6% to 17% on the highway, and 10% to 25% at Interstate speeds (65 mph to 75 mph).
As an alternative, rear-mount cargo boxes or trays are much more fuel-efficient way of transporting the items.
Select the narrowest possible tires for your vehicle that satisfy your driving demands. Narrow tires have less frontal area, thus reducing aerodynamic drag. Two things to keep in mind before downsizing. First is that narrow tires have less traction than wider tires (that’s why race cars and performance cars have wider tires). Second, don’t buy tires that are smaller than what the manufacturer approves or that come stock on the vehicle.