Taking an Electric Car Over the Passes and Up North

Electric cars handle the Bay Area and the valley floor beautifully. The questions start when you point one at Donner Summit in January or at the long stretches of I-5 and Highway 299 north of Redding. None of the problems is a reason not to go. All of them are reasons to plan differently than you would in a gas car.

What cold does to range

The federal fueleconomy.gov site, run by the Department of Energy and EPA, puts numbers on it. In mixed city and highway driving at 20°F, an EV's efficiency can drop roughly 39 percent and its range roughly 41 percent, and about two-thirds of that extra energy goes to heating the cabin. With the cabin heater off, the range loss at the same temperature is about 12 percent. Those estimates are based on a 2019 AAA study, and individual models vary.

The same page gives the practical fixes: preheat the cabin while the car is still plugged in, use the seat heaters instead of the cabin heater where you can, and check tire pressure, which falls in the cold and adds rolling resistance.

Climbs, descents and chain controls

A long climb from the valley to a Sierra summit uses a lot of energy, and regenerative braking wins some of it back on the way down. The result is that the same trip can use noticeably more charge in one direction than the other, so plan to reach the top with margin rather than counting on the descent to save you.

Chain controls apply to electric cars exactly as they do to gas cars. Under an R-2 control, an all-wheel drive EV is exempt only with snow-tread tires on all four wheels and traction devices carried in the car, according to Caltrans, and at R-3 every vehicle needs them. Some EVs have limited clearance around the wheels, so check what your owner's manual allows before you buy chains. And remember that a long hold at a checkpoint or a closure means sitting with the heater running on battery power. Leave room for an hour you did not plan on.

Charger gaps up north

Along the main corridors, fast chargers are spaced for travel. Away from them, in the far north, the eastern Sierra and the coast north of the Bay, they tend to thin out, and a single out-of-service charger in a small town can turn a plan into a problem. Before you go, identify a backup for every planned stop, note which lodging offers overnight charging, and keep the winter range figure in mind rather than the summer one.

When it won't go any further

Running out of charge is a roadside call, the same as running out of fuel, but the tow is different. Manufacturers commonly call for an EV to be carried on a flatbed rather than towed with its drive wheels on the ground, so tell the dispatcher it is electric and check your owner's manual. Some roadside programs offer a mobile charge or a tow to the nearest charger; others simply tow to a shop. A long flatbed tow from a remote stretch is where roadside mileage limits start to matter, so know yours before the trip.

Coverage points specific to these roads

The battery pack sits under the floor, and rural roads throw up rocks, debris and the occasional deer. Underbody damage from striking something in the road is commonly a collision question, while damage from an animal or a falling object is commonly comprehensive; how a claim is classified varies by insurance company. Battery repairs can be costly, which is one more reason people keep both coverages on an EV that is still worth repairing.

Driving in the mountains does not change your premium, since rating uses where the car is garaged rather than where it travels. If you are planning a long winter trip in an EV, you can have your roadside and physical damage coverage checked before you leave.