A car’s environmental footprint is spread over its whole life: building it (the battery especially), the energy it uses on the road, and what happens to it at the end. Looking only at the tailpipe gives an incomplete picture, but looking at the whole cycle still points in a clear direction.
Electric cars: higher footprint at the factory, lower on the road
Making an electric car produces more emissions than making a comparable gas car, mostly because of the battery. That “carbon debt” is paid back after a period of driving, and then the gap keeps widening in the EV’s favor. Life-cycle studies by the International Council on Clean Transportation and others find that, in the US, Europe, China and India, a mid-size battery electric car registered today has clearly lower lifetime emissions than a gas-powered equivalent. The cleaner the local electricity, the bigger the advantage.
The size of the car still counts. A compact EV with a moderate battery has a much smaller footprint than a heavy electric SUV or pickup with a huge pack.
Hybrids: a strong middle ground
If an EV does not suit your situation (no home charging, very long trips, or a tight budget), a full hybrid cuts fuel use substantially, especially in town, with no change in how you refuel. Plug-in hybrids can be even better, but only if they are actually charged. Driven on gas most of the time, they carry a heavy battery for nothing.
Small and efficient still matters
The most sustainable car may be the one you already have, or a small used one. Keeping a car running longer spreads the emissions of its manufacture over more miles, and a light, efficient compact that you drive moderately can have a smaller footprint than a new large vehicle of any type. You can compare tailpipe and estimated upstream emissions for specific models on the EPA’s fueleconomy.gov, which includes a calculator for electric cars based on your ZIP code’s electricity mix.
Beyond the drivetrain
A few other choices make a difference:
- tires with low rolling resistance, kept at the right pressure;
- buying the smallest car that fits your normal needs, not the rare exception (rent for those);
- driving smoothly and reasonably slowly on the highway;
- recycling properly at the end of life, including battery take-back for EVs.
Many of these apply to any car you already own, and we go through them in how to make your car more eco-friendly. If you are weighing the switch to electric, our article on whether electric cars are the future covers the practical side, and the guide to fuel-efficient cars helps if you are staying with gasoline for now.
