Earth Day was April 22, and the challenges highlighted in the latest IPCC report have given added urgency to its usual message, take care of our planet. This year, Ars takes a look at the technologies we typically cover, from cars to chip manufacturing, and finds out how we can boost their sustainability and minimize their climate impact.
For many people, the purchase of an electric vehicle is a challenge: if I am going to drive around the city, I will do it while reducing my carbon footprint.

“Gone are the days of burning toxic gasoline. A new age of electrons and instant torque is upon us,” he might say, standing next to his new vehicle and blue recycling bin.

EVs require more energy to build, but they are far more efficient to operate.

But just like traditional vehicles, not all electric vehicles are equal in their impact on the world. A quick look at the specs and size of the new GMC Hummer EV is all you need to understand where some automakers are willing to take the powertrain, and it's not in the service of efficiency.

Not all EPA tests are created equal
If you want to determine which electric vehicles are the most efficient, a good place to start is the fuel economy ratings from the Environmental Protection Agency. The EPA lists electric vehicles based on the amount of energy they use to travel 100 miles, and the lower the number of kilowatt-hours of electricity used, the more efficient the vehicle. For example, according to the EPA, the 2022 Tesla Model 3 RWD uses 25 kWh per 100 miles, while the 2022 Audi e-tron S (with 21 or 22-inch wheels) uses a less efficient 52 kWh per 100 miles. travelled. (Note that larger wheels generally reduce a vehicle's range.)

For the 2022 model year, these are the five most efficient vehicles on sale right now based on the EPA's measure of energy used per 100 miles:

2022 Tesla Model 3 RWD: 25 kWh
2022 Lucid Air Grand Touring: 26 kWh
2022 Chevy Bolt: 28 kWh
Hyundai Kona electric 2022: 28 kWh
Tesla Model S 2022: 28 kWh
The top 10 finishers were the Model Y, Bolt EUV, Kia EV6, Hyundai Ioniq 5 and finally the Kia Niro, all of which posted 30 kWh of energy use per 100 miles or less.

These are impressive numbers, but there is something else to consider, namely the adjustment factor used to determine the EPA range data. To get these numbers, all electric vehicles are hooked up to dynamometers (like a car treadmill) and run until the battery runs out. It's not a real-world test, as the vehicles don't have to deal with changing elevations, wind, discrepancies in the asphalt, and all the other issues they'd encounter on real roads.


To complicate matters a bit more, some automakers take the EPA's 30 percent adjustment factor. For example, if a vehicle goes 500 miles on the dyno, the automaker takes a 30 percent hit, reducing that range by 150 miles, giving it 350 miles of range on the EPA cycle. It is the method used by Hyundai, Kia and GM.

Tesla and Lucid do something different. They make additional runs on the dynamometer and are allowed to use those results to produce better fit factors. Those numbers help increase your rank numbers.

So while the EVs listed above are certainly efficient, they're not all tested in the same way and that can lead to discrepancies.

factory impact

As automakers are transitioning to battery electric vehicles, they are also promoting their current or future carbon-neutral factories. A cleaner factory results in a cleaner vehicle coming off the line. It's a laudable plan, but for many manufacturers it's a promise that has yet to be fully implemented.

Tesla seems to have the most difficulty in this area at its factory in Fremont, California, where it makes all the vehicles it sells in the United States. In February 2022, the automaker settled with the EPA over Clean Air Act violations that stretched from 2016 to 2019. In 2019, the EPA fined the company for hazardous waste violations, and in May 2021, the Bay Area Air Quality Management District fined the company $1 million for violations, including exceeding its allowable emissions.

The Lucid Air is built at the company's new Arizona factory. The 500-acre property in Casa Grande, Arizona, opened in the fall of 2021, but the company has not yet announced any energy-reduction or carbon-neutral initiatives at the plant.