How can a topper affect your fuel economy?
Before we get into the surprising results, a bit of context. In today’s video, Andre tests out our 2004 Ford F-150’s fuel economy, both with and without a topper fitted to the bed. According to EPA figures, the 18-year-old truck should manage somewhere in the region of 18 MPG on the highway when unladen. For this test, we’re using a 54-mile highway loop to see just how the topper off figure compares to the fuel economy with the topper installed.
It’s a question we’ve often been curious about. There are plenty of tests out there if you’re researching the subject, and we wanted to see just how we could manage in real-world driving conditions. Andre takes the Ford F-150 out at 70 MPH for exactly 53.96 miles, tracked using a smartphone-based GPS app. Since we lifted the truck and fitted larger 33-inch tires for our “To Hell and Back” series, the speedometer is not currently calibrated properly for this sort of test, so using any onboard equipment — including the trip computer, if this base XL truck actually had one — wouldn’t work.
Surprisingly, the old Ford F-150 still managed to hit what the EPA suggests it should pretty much bang out. Without the topper fitted, the truck managed 18.16 MPG. What’s more, even when it’s on the truck, the aerodynamic benefits seem to outweigh the extra weight.
When Andre put the topper back on and ran the loop again, the truck managed 18.26 MPG. Even factoring in a reasonable margin of error, that result is so close that it seems to make almost no difference whether or not you decide to install a topper.
Check out our full test below: