Do Tonneau Covers Actually Improve Your Truck's Gas Mileage Or Is That Just Something Your Weird Uncle Told You?

There are few things that I love more than getting to the bottom of a good bit of bro science, and that's exactly what's going on today. Since the dawn of the pickup truck bed, drivers have been trying to figure out ways to eke out better gas mileage from the aggressively not-aerodynamic piece of body structure. That has been magnified by the sharp rise in gas prices we've seen over the past month or so. One of these solutions for better gas mileage in a pickup truck is fitting it with a tonneau cover, but does it actually make any difference? Well — as with everything in this world — the answer isn't exactly clear-cut.

Of course, even outside of perceived fuel economy gains, tonneau covers are a useful way to keep whatever junk is in the bed of a truck secure and out of the elements, but we don't care about that today. The only thing we care about is saving on gas, and to do that, we need a specific type of tonneau cover, because that's what makes all the difference. The key is looking for lightweight covers — usually soft roll-up or soft folding covers — rather than heavier, more rigid covers, according to Real Trucks, a truck enthusiast website that actually went out and ran fuel economy tests themselves.

A writer at Forbes found that putting a tonneau cover on a Ram 1500 TRX improved the truck's highway fuel economy from somewhere between 8 and 9 miles per gallon to between 11 and 12 miles per gallon. It's clear that an appreciable difference — while small — is there. Anecdotal, he found that his overall fuel economy improved by nearly 10%.

Real Trucks says these types of covers are able to reduce a truck bed's coefficient of drag by 5%, and that's apparently a conservative estimate from them. In the end, that works out to a nearely 2% improvement in fuel economy. That may not sound like a ton, but it makes a difference over a long enough period. These days, every little bit helps.

The thing is, not every tonneau cover is created equal, and not all of them will help pickup truck drivers achieve their slightly better fuel economy goals. Bulky, heavy-duty tonneau covers will carry the same sort of aerodynamic advantages as lighter ones; the fact that they're so heavy will negate any potential gas mileage improvements.

One thing we haven't really discussed yet is money, and that's where things get tricky, because it's not like tonneau covers are free. Sure, there are some crappy ones out there you can get for a few hundred bucks, but really good ones will set you back $1,500-$2,500, depending on the truck's bed size, the company and the material it's made out of. I know pickup trucks can be quite thirsty, but it's going to take a hell of a lot of time to make up that sort of money when you're only seeing a 2% gain in fuel economy.

Still, for most truck buyers (read: people who aren't using their trucks for Work Stuff), tonneau covers definitely make sense — not only because they can theoretically improve fuel efficiency, but because they can keep cargo out of harm's way. Truck owners really just want a big trunk, and that's what a tonneau cover really does, at the end of the day.