[Auto] Testing Our Rivian R1T Shows How Cold Temps Affect an EV's Range

[Wolf.17]

 

The U.S. Department of Energy says an EV's range can drop by around 41 percent in subfreezing temps, so we used our long-term Rivian R1T to explore that claim.

In our real-world highway range test, we saw the R1T's result drop from 250 miles on a 42-degree day to 190 miles in 12-degree weather—a 27 percent difference.

While the cold didn't affect our electric truck's range as much as the DOE suggests, there are myriad factors at play, and EVs manage extreme temps in different ways.

 

Welcome to Car and Driver's Testing Hub, where we zoom in on the test numbers. We've been pushing vehicles to their limits since 1956 to provide objective data to bolster our subjective impressions (you can see how we test here).

This past winter in Michigan, where our editorial office is based, was the warmest in 125 years, according to the National Weather Service. Still, there were days below freezing that prevented Detroit from feeling like the Maldives. Not that anyone could mistake the two. When temperatures drop, so does the efficiency of vehicles. This information is neither new nor only applicable to electric cars, but we did feel compelled to illustrate this issue with another test.

The U.S. Department of Energy says a gas-powered car's fuel economy can be as much as "15 percent lower at 20 degrees Fahrenheit than it would be at 77 degrees Fahrenheit." However, the effect is far more dramatic with electric vehicles. The DOE says that "fuel economy can drop roughly 39 percent in mixed city and highway driving, and range can drop by 41 percent" for EVs.

Those percentage drops in efficiency are enough to give anyone the chills. With a 7054-pound Rivian R1T electric truck at our disposal, we decided to test the government's estimates using our 75-mph real-world highway range test in normal and below-freezing temperatures.

When our long-term Rivian arrived nearly a year ago, it completed a range test in 42-degree weather, traveling 250 miles from 100 percent to zero. That's 39 miles short of its estimate, but considering how few EVs ever come close to matching their EPA estimate in our highway test, the 14 percent delta is respectable.

During a 12-degree day, the same dual-motor R1T, albeit with fresh tires and about 20,000 miles of everyday use, managed to travel only 190 miles during our highway range test—a 27 percent drop in range at a 30-degree drop in temperature. So, not as scary as the DOE's estimate, but enough to make us curious.

One could argue using cold weather accessories such as heated seats, a heated steering wheel, and a more aggressive climate-control setting to heat the cabin all contribute to higher energy use during the winter. But while it's true more powered items do increase consumption, we always do our range tests the same way with the climate set to 72 auto and no other accessories, such as heated or ventilated seats.

https://www.caranddriver.com/news/a60306924/rivian-r1t-cold-temperature-ev-range-test/