Auto exhaust is a major source of carbon dioxide accumulating in the earth’s atmosphere, and an increasing number of conscientious motorists are turning to more efficient personal vehicles to help mitigate the escalating climate crisis. Three modern powertrains are currently responsible for the vast majority of tailpipe emission reductions, with battery electric vehicles (BEVs) providing the greatest benefits. As the steady transition away from internal combustion vehicles progresses, hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs) are playing an important supporting role, offering beneficial options to motorists who are reluctant to drive BEVs. When purchasing any EV out of concern for the environment, it is important to remember that there are numerous variables that affect a vehicle’s emissions. For any given powertrain, efficiency will vary considerably from one model to the next. Each of the three major green powertrains has its own U.S. fuel economy champion, and a consumer purchasing any of the three should feel satisfied with their contribution to the international climate effort.
When evaluating a BEV’s environmental benefits, upstream emissions and energy conservation are important considerations, and the miles-per-gallon-equivalent (MPGe) rating is the main specification to watch. The MPGe figure provides the number of miles that a BEV can travel using 33.7 kilowatt-hours of electricity, which is the same amount of energy found in one gallon of gasoline. Of all the 2024 light duty vehicles sold in the United States, Hyundai’s fully electric Ioniq 6 SE long-range rear-wheel-drive generates the smallest quantity of carbon dioxide. Its extraordinary 140 MPGe rating is as good as it gets, allowing the sleek sedan to travel 361 miles on a single charge.
For altruistic folks who are hesitant about driving a BEV, an efficient hybrid is an excellent option. HEVs have been reducing global tailpipe emissions for over two decades, and efficient models continue to deliver valuable environmental benefits. Comparing the emissions from an HEV to a conventional gas burner is straightforward, since both are rated using the same MPG metric. Toyota’s 2024 Prius LE front-wheel-drive is the most efficient HEV sold in the United States, boasting a stellar MPG rating of 57. The hatchback’s MPG figure is over twice as high as the average MPG of all new light duty vehicles sold in the U.S. during 2022, which was 26.
PHEVs combine the efficiency of hybrid technology with the ability to travel moderate distances on imported electric fuel. A plug-in hybrid receives an MPG rating for its gasoline fuel economy, an MPGe rating for its electric fuel economy, and an electric range rating that quantifies the distance it can travel using stored electricity. Toyota’s 2024 Prius Prime SE outperforms other PHEVs by a wide margin, achieving an MPG of 52, an MPGe of 127, and an outstanding electric range of 45 miles. When powered by electricity, the Prius Prime’s superior MPGe rating is comparable to some of the most efficient BEVs. On longer journeys, its sophisticated hybrid engine consumes gasoline sparingly, providing 600 miles of total range.
If you are planning to support the climate effort by buying a BEV, an HEV, or a PHEV, you are to be commended. Whatever powertrain you choose, your purchase will make the biggest impact if you select a model with exceptional fuel economy.
