If you’re thinking about buying an electric vehicle (EV), arguably the most important specification to consider is how many miles it can travel on a charge. This is known as an EV’s range. Worrying about whether or not an EV’s battery pack will become depleted and strand you at the side of the road before arriving at a given destination is called range anxiety. The idea here is to choose a model that can run for long enough on a charge to meet your daily transportation needs without causing undue anxiety. Americans drive an average of 40 miles a day, according to the U.S. Department of Transportation.

Most EVs for 2018 can run for between 100-125 miles with a fully charged battery pack. With battery technology evolving rapidly, some of the latest models boast the longest operating ranges. The best of the bunch, which we’re featuring in the accompanying slideshow, can run for well over 200 miles before needing to be plugged back into the grid.

The Tesla Model S is the industry's current champ, estimated to travel a whopping 335 miles per charge with its longest-range battery pack. At the other end of the scale, the tiny two-seat Smart ForTwo Electric Drive is the EV most likely to induce range anxiety, with a paltry 59 miles per charge.

Official range estimates, along with equivalent “fuel economy” ratings (this is expressed in terms of “e-mpg”) for all EVs sold in the U.S. past and present are posted on the Environmental Protection Agency’s fueleconomy.gov website. But be aware that these are estimates based on the EPA’s instrumented analysis, and as they say in new-car ads, “your mileage may vary.” A number of factors can affect an EV’s range out in the real world:

Speed: Unlike conventionally powered cars, electric vehicles consume more energy running at highway speeds than they do around town. Likewise, jack-rabbit starts and sudden braking can take a toll on an EV’s battery range.

Temperature: Cold temperatures adversely affect a battery’s performance. According to a study conducted by the AAA Automotive Research Center, an EV’s operating range can vary considerably based solely on the ambient temperature.

Accessory Use: Using the heater, defroster or air conditioner places the most drain on an EV’s battery among all auto accessories. Preheating or cooling down an EV’s cabin while it’s still plugged into the charger can help extend its range.

Wind Resistance: As with conventionally powered cars, EVs consume more energy when overcoming wind resistance. That’s why automakers pay such strict attention to a vehicle’s aerodynamics. Driving at highway speeds with the windows or a sunroof open will increase a vehicle’s wind resistance. So will driving with a roof rack or other exterior accessories installed.

Terrain: It takes more power to drive any vehicle uphill than it does to go downhill.

With an estimated operating range of 151 miles, the revamped 2018 version of the popular Nissan Leaf can run for about 50 percent longer on a charge than last year’s model at 107 miles. In terms of its equivalent fuel economy, the EPA rates it at 125/100 (city/highway) e-mpg.

The Chevrolet Bolt subcompact hatchback is the brand’s Tesla fighter. It’s peppy and roomy and it can be driven in “one pedal” mode with the car’s regenerative braking system slowing down the vehicle when lifting off the accelerator. It’s rated at 128/110 e-mpg.

The Tesla Model X is the automaker’s least-efficient model, yet it still beats most EVs with an estimated operating range of 238-289 miles, depending on the version. That’s particularly impressive considering this is a rather large and heavy all-wheel-drive crossover SUV. It’s EPA-rated at 91/95 e-mpg.

The Tesla Model 3 is the upstart EV maker’s latest vehicle, and it’s a sleekly cast midsize sedan with a truly practical operating range. It’s rated at 136/123 e-mpg (120/112 e-mpg with the optional all-wheel-drive system).

Still futuristic-looking inside and out after six years on the market, the Tesla Model S sedan offers a choice of battery packs that afford between an estimated 249 and a class-leading 335 miles on a charge for 2018. The most energy-efficient Model S is EPA-rated at 102/105 e-mpg.