Combustion cars tend to be more efficient in highway driving. But with EVs, that picture can be inverted. Electric vehicles perform well in stop-and-go city driving, where they idle efficiently and replenish their batteries with regenerative braking. It’s on the highway where some (but not all) EVs struggle to hit their range numbers. For example, the Kia EV9 GT-Line AWD is rated for 270 miles but earned just 240 miles in Car and Driver 75 mph highway testing.
EVs losing range on the highway is unfortunate. A chief source of range anxiety that wards off many prospective EV buyers is how much range an electric car would have on a highway road trip that would necessitate trips to a public charger. And it wouldn’t be summer without taking just such a road trip.
There’s no broad panacea for EV highway range issues. But there are a few tricks you can use at the margins to ensure your EV delivers its maximum amount of range it can between stops.
Pre-condition the cabin before you leave
Many EVs offer the option to pre-condition the cabin before your departure. Do this. Pre-conditioning the cabin while on the charger puts the initial, energy-intensive part of the air conditioning process on the grid power rather than the battery, so it doesn’t affect your range. It takes comparatively little energy to keep the cabin cooled once you depart. Pre-conditioning is extra important for EV owners in winter, as heating the cabin typically requires more energy than cooling it.
Check your tire pressure
Tires naturally lose PSI over time. Deflating tires increases their rolling resistance, increasing the energy required to push the car forward. Drawing more power from the battery limits the range. Topping the tires back up to the manufacturer-recommended settings can help mitigate that.
Drive slower
The U.S. didn’t impose a 55 mph national speed limit in 1974 to irritate Sammy Hagar. The government’s goal was to reduce energy consumption during a fuel crisis. Driving slower uses less fuel. EVs get their energy from batteries rather than internal combustion, but the same principle applies. The faster you drive on the highway, the more energy you need to overcome drag. That exacerbates as your speed gets higher. You’ll get a longer range when driving closer to the speed limit than you will when going 15 mph over.
Use cruise control
Restraining your throttle inputs is an excellent way to preserve battery life. Cruise control, particularly in flat areas, will help your EV maintain a constant speed without slowing down and speeding up as much as you would. Many EVs also have an Eco Mode, which can help keep the throttle inputs in check while cruising.
Simplify, then add lightness
As with a combustion vehicle, using cargo carriers, bike racks, or other accessories adds drag to the car and increases the amount of energy required to move it through space. That will reduce the range, as will adding a lot of weight to an already heavy EV. Consolidation while packing can be difficult, especially if you have kids, but any efforts in that direction should help mitigate range loss.
