Researchers are calling the eco-friendliness into question, but General Motors says the research is missing the point. A study the released in June claimed the has higher CO2 emissions than a . The electric Hummer’s are partially caused by fossil fuels in the U.S. power grid, but, mainly, because the Hummer EV is .

Now, GM has released a statement in response that says the study overlooks the value of the Hummer EV as a trojan horse to win hearts and minds in the U.S.:

The study ignores the real-world importance and benefit of bringing to market performance oriented EVs like the GMC Hummer EV [...] Seventy five percent of the tens of thousands of customers who’ve reserved a Hummer EV have never owned an EV – many are or were pickup owners. The GMC Hummer EV (and other performance-oriented EVs) are accomplishing more in bringing EV skeptics into the EV fold than any of these half-glass-empty criticisms ever will.

GM’s claim that the Hummer EV is helping convince buyers in the U.S. to go electric reads like an evasion. Or justification. It doesn’t address the criticism.

General Motors gave and the same statement, after they cast doubt on the Hummer EV as an environmentally-conscious vehicle. The term “eco-conscious” is implied in “EV,” but the study says that not all EVs are created equal. Indeed, EVs are far from being equally efficient, which is what researchers focused on.

Researchers said the gas-powered Malibu makes 320 grams of CO2 per mile while the Hummer EV makes 341 grams. These emissions don’t come from the Hummer EV’s tailpipe (there isn’t one) but from energy sources in the U.S., since 60 percent of the power grid relies on fossil fuels.

This dirty power is kind of an open secret, and shows that even in the dirtiest grid, EVs eventually produce less CO2 per mile than ICE-powered cars. The problem with the Hummer isn’t energy; it’s mass and energy conservation.

With efficiency as a metric, we can forget about the Malibu; we don’t have to compare EV and ICE, since the Hummer EV (341 grams) makes three times the upstream CO2 emissions of GM’s own (92 grams).

The Hummer EV is : it’s 18 feet long, 7.25 feet wide, and 6.5 feet tall. It weighs more than 9,000 pounds, and, yet, it goes from 0-60 in three seconds. That’s why GM calls it a “performance-oriented EV,” but the ACEEE finds it’d be better known as an inefficient EV. It burns comparatively more energy to cover its range, and it’s down to size and weight. Here’s the efficiency of a few EVs, according to the study, based on weight and measured in kilowatt-hours.

I wish the Hummer EV were on the chart, but it’s not because the weight only goes up to 7,500 pounds. If the Hummer was smaller or weighed less — given a lighter battery or if GM opted for less range — it could hardly be compared to a Malibu. The study concludes that the should factor efficiency into new EV standards. Right now, they all get the same blanket rating of zero emissions, which is wrong. Or, we could always listen to GM and just make new categories: performance EV, commuter EV, eco-friendly EV.