The 2024 American Council for an Energy Efficient Economy (ACEEE) list of “meanest” vehicles for the environment includes the expected array of gas-guzzling trucks—but also one EV.

The 2024 GMC Hummer EV SUV was ranked ninth on the list, between the GMC Sierra pickup truck and Mercedes-Benz G550 SUV. The annual list is based on the estimated health and environmental impacts associated with a vehicle’s “tailpipe” emissions, as well as emissions from production and distribution of the fuel or electricity used to power it, as well as emissions related to manufacturing and disposal.

The Hummer EV has much lower estimated “fuel” costs than the other vehicles on the list. Estimated annual cost, based on 15,000 miles of driving, is $1,746, compared to $4,242 for the Mercedes-AMG G63, was ranked as the “meanest” 2024-model-year vehicle for the environment overall.

As always, the ACEEE also published a list of “greenest” vehicles for the environment, which this year was topped by the Toyota Prius Prime SE. The plug-in hybrid’s estimated annual fuel cost of $529 puts the Hummer EV’s inefficiency in perspective. Two EVs—the Lexus RZ 300e and Mini Cooper SE—were ranked second and third, respectively.

2024 GMC Hummer EV SUV

Previous versions of the “greenest” and “meanest” lists have also shown that lighter EVs are the greenest. Lighter vehicles that carry more people has been a longtime formula for making vehicles more environmentally sound. And the Insurance Institute for Highway Safety (IIHS) has warned that excessive EV weight is a safety concern.

Worse yet, the Hummer EV may enable General Motors to build more gas-guzzling trucks. The electric Hummer’s circa 9,000-pound curb weight exempts it from EPA emissions standards for passenger vehicles, but fleet rules may give GM the flexibility to use Hummer sales to offset those of gasoline and diesel trucks. So it’s tread heavy and tread heavier.