Removing This Common Car Accessory Has A Major Impact On Fuel Economy

Gas prices are likely to remain elevated in the immediate future, so Americans looking to cut their gas bill have two choices: drive less or improve their car's fuel economy. Anyone in the market for a new vehicle has plenty of options when it comes to picking the most fuel-efficient car for their needs, but many drivers could significantly boost their existing car's fuel economy by optimizing how they drive. The list of ways to avoid wasting fuel is a long one, and one of the easiest ways is to remove any roof boxes or roof racks from your car when they're not in use.

The exact amount of fuel you could save will vary based on the type of roof rack you own, since some are significantly more aerodynamically efficient than others. In many cases, the savings might be more than you think. A test by Car and Driver found that removing the factory-fitted crossbars from their Kia Carnival minivan increased efficiency by 12%, while Consumer Reports saw the mpg figures of their Nissan Altima drop by 11% when they fitted a roof rack.

It isn't just roof racks, either, since any kind of roof-mounted cargo will have a negative effect on efficiency, for both ICE cars and EVs. An analysis published by The New Climate calculated that a Tesla with a 360-mile range would drop to around 310 miles if two kayaks were carried on its roof.

Most of the efficiency drop caused by unnecessarily carrying a roof rack is due to increased drag. More drag means the car's engine has to work harder to reach and maintain high speeds, and the faster you go, the more effort is required. That means drivers who remove roof racks will see the biggest efficiency improvements when traveling at highway speeds, although even drivers who cover most of their mileage at lower speeds should still notice a difference.

If your roof rack is filled with especially heavy cargo, you might notice an even bigger difference in your car's fuel economy when you remove it. According to EPA estimates, carrying around an additional 100 lb of cargo can reduce your car's fuel economy by around 1%. Smaller vehicles will see a bigger drop in efficiency if they're carrying excess weight. 

In addition to removing unnecessary cargo from the roof, it's also worth making sure you are not carrying any excess cargo in your car's trunk. To keep your trunk clutter-free, it's worth investing in a trunk organizer to keep smaller items from getting lost.