The SUV vs the EV

Today, exactly one SUV gets better than 30 mpg – the hybrid Ford Escape (pictured here), so it's hard to imagine much room for sports utility vehicles in 2025, when the average vehicle must get 40 mpg.

Right? Not so fast, lead foot.

As we try to envision the car lot of the future, confounding devils come out in the details about vehicles on opposite ends of the fuel-economy spectrum, SUVs and EVs – sports utility vehicles and electric vehicles.

While the new rules mean that the average car must be 5% more fuel efficient each year, so-called "light trucks" – SUVs, minivans and pickups – could progress at a more leisurely 3.5% annual improvement rate, NRDC's Hwang said. Basically, that means more gas-guzzling SUVs and pickups will remain for sale in 2025 than would be the case without the loophole. And different automakers will achieve different levels of fuel economy, according to Edmunds.com's O'Dell. Today GM's fleet has more gas-guzzlers and a lower overall fuel economy than Honda's fleet, which is dominated by smaller cars; that type of discrepancy will remain.

And, Hwang added, robust sales of electric vehicles could, paradoxically, also lead to additional sales of SUVs. The new fuel-economy standards are designed to reduce pollution and gas consumption, and EVs do both extraordinarily well, since pure electric cars use no gas and emit no tailpipe emissions. As automakers average in zeroes for their fleets of EVs, then, they could also sell more gas-guzzling SUVs, pickups and minivans.

"The more electric vehicles they make, the more dirtier gasoline vehicles they can make," Hwang said. "What you gain in EVs you lose in less efficient and dirtier gasoline vehicles."

That's why NRDC is lobbying the EPA to put a cap on the number of zero-emissions electric vehicles like the Nissan Leaf (pictured here) that automakers can claim. After all, the pollution from driving an electric vehicle isn’t zero; it just comes out of the smokestack of the local power plant, rather than the tailpipe of the car.

Hybrid cars, including hybrid full-sized pickup trucks, will also qualify for credits, Sinnamon said. Those credits will allow automakers to double count hybrid vehicles when calculating average mpg, leaving them plenty of room on the lot for bigger vehicles. Plus, because the 55 mpg fuel economy standard is based on the efficiency needed to achieve greenhouse gas emission goals, automakers can also take advantage of additional credits for things like swapping air conditioning refrigerants for climate-friendly options.

Bottom line: Loopholes, credits and fuel-economy accounting will ensure that SUVs, pickups and minivans will still be on the market in 2025, despite the new tighter fuel-economy standards.