This section makes the test suspect.
Because driving in the cold and running the
heater can shorten an EV’s range between 25 and 50 percent, we perform all our range tests in summer at temperatures between 70 and 90° F and when weather is clear, which is the most favorable for EV range. If we purchase a new vehicle at another time of the year, we will initially score it based on its EPA range until we can perform our own tests.
We control the tests in other ways as well, setting tire pressure to factory specifications, preconditioning the vehicles inside our garage, setting climate control to 72° F, and using cruise control with speed and mileage verified via GPS. To better understand what drivers experience when range gets critically low, we also document what warnings the vehicles provide. We set regenerative braking to the lowest level, and we also test vehicles in Eco mode, if the car has it, to maximize range the way drivers would likely do on a road trip. If there’s a significant slowdown on our route, we restart the test.