This Simple Bike Rack Switch Could Have A Major Impact On MPG

Adding a bike rack to your car is a fantastic way to transport your bikes on road or camping trips, but any change to the weight or aerodynamics of your vehicle can affect your MPG. That said, a simple way to minimize the impact while maximizing space in your car is to trade out a roof mounted rack for a hitch rack.

Per testing conducted over at Consumer Reports, adding any bike rack to your car will decrease your fuel efficiency. However, the impact is significantly lessened if the rack is behind your car rather than mounted on the top. This is likely due to the fact that a roof-mounted rack has a much bigger impact on the aerodynamic silhouette of your vehicle, forcing your engine to work harder (and consume more fuel) to overcome the increased air resistance.

Consumer Reports tested both an empty rack and a rack bearing two bikes on a Nissan Altima sedan and a Toyota RAV4 SUV and found that even a bare rack added a small efficiency penalty, much increased in the roof position, and that overall the SUV handled the impact of a rack better, regardless of load and position.

A hitch rack can save you significant fuel vs. a roof rack, particularly on long trips. Consumer Reports found that a roof rack on the RAV4 loaded with two bikes cost 19 percent more MPG, while a hitch rack with the same pair of bikes only cost 12 percent more. On the sedan, the penalty was higher, though the difference between laden roof and hitch racks was reduced, with the roof rack costing 28 percent more fuel and the hitch 25 percent. The difference was much more noticeable when the racks were empty, costing 11 percent for the roof model and only 3 percent for the empty hitch.

One of the downsides is that, like these other accessories, adding a hitch rack means you can't have a spare tire mounted to the back of a vehicle like a Jeep or similar SUV. A hitch rack can also block your access to your truck or hatchback space, as well as obscuring rearview cameras that activate when you're backing up. A hitch rack can in some cases also trigger a false positive for sensors meant to detect when there's an object behind the car you're in danger of backing into.

That said, a hitch rack is generally easier to install (or remove) than a roof rack, and much easier to secure a bike to; no more hoisting a bicycle over your head like Hercules or having to haul out a step ladder. Lots of platform-style hitch racks also hold the bikes by their wheels, which can avoid any concerns around your bike banging into your car's chassis while you're driving.