Cybertruck tonneau cover an efficiency win, at least 25 miles of range lost when open at 75 mph

Since the Tesla Cybertruck was launched in late 2023, there have been a bevy of reviews and tests pouring over the vehicle's positives and negatives and evaluating everything from its build quality to its off-road prowess. The latest Cybertruck test out of Car and Driver featured a detailed look at the electric pickup truck's efficiency, and the results turned out to be less than stellar for anyone that was hoping to fill the bed with stuff on a regular basis.

Car and Driver tested the Cybertruck's efficiency in a number of scenarios, but most importantly, it compared the difference in efficiency when the tonneau cover was closed to when it was open. The test was conducted at 75 mph (ca. 121 km/h) and on a test loop to eliminate wind interference.

While the Cybertruck turned out to be more well-thought-out than its angular dimensions might suggest, delivering a consumption figure of 58.3 kWh/100 mi when the tonneau cover was closed, that figure dropped by over 10% to 64.2 kWh/100 mi when the bed was open. This is only slightly worse than the smaller Rivian R1T's estimated 50 kWh/100 mi figure.

Car and Driver estimates that opening the tonneau cover would drop the Cybertruck's real-world range from 250 miles (ca. 402 km) to around 225 miles (ca. 362 km) — a 10% decrease. Even more interestingly, the Cyber Wheel Covers, which Tesla recently pulled from all new Cybertruck deliveries, had a measurable impact of around 1.7% on overall efficiency.

The results were similar at 65 mph (ca. 105 km/h), although with lower consumption overall. With the tonneau cover closed and driving at 65 mph (ca. 105 km/h), the Cybertruck's estimated range jumped up to 295 miles (ca. 475 km). When the bed was open, the Cybertruck was using 54.2 kWh/100 mi at 65 mph (ca. 105 km/h), compared to 49.3 kWh/100 mi with the bed closed at the same speed.

Even though the test results point to a 10% drop in range, the reality will likely be even worse, when you consider that most scenarios in which the tonneau cover is open will involve either something sticking out of the top of the Cybertruck's bed, like tall furniture, motorcycles, or building supplies. The added turbulence and weight from objects like these on the bed of the Cybertruck will almost certainly be a significant detriment to the range of the EV.

This efficiency drop holds true for basically all pickup trucks, electric or not, but it may seem more painful to drivers of electric pickup trucks because charging can be a bit of a hassle, depending on where you find yourself when the battery runs low. Previously, a tech YouTuber found that the Cybertruck could only tow something close to its maximum capacity of 11,000 lb (ca. 4,990 kg) for just over 100 miles (ca. 161 km) before running out of juice.

Buy a Cybertruck 1/24 die-cast metal toy car on Amazon, or read about the Cybertruck's development in Walter Isaacson's biography of Elon Musk.