Range Buffer

How much range does an EV lose in winter?

The range figures in this calculator are EPA ratings from mild test conditions. The site has no cold-weather measurement for any model, so any exact winter percentage would be a guess. Treat rated range as a ceiling and widen the buffers when it is cold.

The calculator multiplies rated range by (1 minus reserve) and by (1 minus derate). The defaults of 15 and 15 turn a 320-mile rating into 231 usable miles. A winter plan might start at 20 percent reserve and 25 percent derate, which gives 192 miles. Those two settings are a starting point to adjust once you see how your own car does through a real winter.

Do heat pumps help EV range in the cold?

Cabin heat is a large extra load in winter. A resistive heater turns electricity into heat roughly one for one, while a heat pump moves heat and gets more warmth per kWh in most conditions. Of the 43 current models with the field recorded, 38 list a heat pump. The five that do not are the Ford Mustang Mach-E, Jeep Wagoneer S, Lucid Air, Rivian R1T and Dodge Charger EV. That is a design fact, and the data does not show how much range each loses.

Does efficiency matter for winter range?

A car that uses fewer Wh per mile has more margin before cold weather becomes a problem. The two traits do not always come together. The Lucid Air has no heat pump but rates 264 Wh/mi, while the Kia EV9 has one and rates 380 Wh/mi. Check both specs on the trim you are considering.

Does cold weather slow DC fast charging?

A cold battery accepts fast charging more slowly, and warming it on the way to a charger (preconditioning) helps. The data records preconditioning for only 11 of the 58 models, so check the specific car. For winter road trips, run the stop through the charging-time calculator and add time to the result.