ACEEE Green Car Ratings: No Respect for Weighty Tesla

By · January 27, 2014

Smart ED Cabrio

The Smart Electric Drive Cabrio rocked the "Greenest Car" rankings from ACEEE. (Jim Motavalli photo)

Say hello to the "Greenest" car on the U.S. market, the Smart Fortwo Electric Drive. It got a score of 59 in the annual ratings, released today, from the American Council for an Energy-Efficient Economy (ACEEE), but that doesn’t mean that every electric car won the group’s respect. In fact, some were outright dissed.

ACEEE uses a complex set of variables to determine its green scores, and weight and manufacturing emissions matter a lot. Shruti Vaidyanathan, ACEEE’s lead vehicle analyst, told me that building a car can produce 20 percent of its lifetime emissions, which is higher than I’ve heard from the group in the past. A 37 for the zero-emission Tesla Model S with 85-kilowatt-hour battery pack? The same score as the Toyota Tacoma pick-up? Why?

“We rated the Tesla this year, and it’s a heavy vehicle with a heavy battery,” Vaidyanathan said. Weight is one of the biggest determinants.” The lighter 60-kWh Model S was rated 38. Besides the Smart, the electric car that did especially well, at number 3 on the list, is the Nissan LEAF. “That’s a very light electric car,” Vaidyanathan said, “around 3,500 pounds.”

There are both “Greenest” and “Greener Choices” lists, with the latter showcasing cleaner cars within categories, including SUVs and trucks. Thus the Ram 1500 HFE and Nissan Rogue are on the “Greener Choices” list, but the Chevy Volt is not, nor are any cars with plugs. The Chevy Volt didn’t place, even though it scored a decent 50. Three versions of the Prius trumped on the “Greener” list with best compact (Prius C), midsize (Prius) and midsized wagon (Prius V). All scored (barely) higher than the Volt.

Averaging the Grid

Obviously, electric cars are generally greener in states with cleaner grid electricity. EV scores do reflect the grid, but not locally—the national grid is averaged for ACEEE’s evaluation purposes.

Plug-in fans will probably rankle to see cars like the conventional Mitsubishi Mirage, with a score of 54, on the “Greenest” list but the Honda Fit EV (56) and RAV4 EV (43) nowhere to be seen.

Other EV rankings include the Chevy Spark (58), Fiat 500e (57), Honda Accord Plug-In Hybrid (52), Ford Focus Electric/C-MAX and Fusion Energi (all 51), and Porsche Panamera S E-Hybrid (37). That last one's gotta hurt.

My first impression of this year’s ACEEE list is that the ratings put a little too much weight on weight, and the scoring methodology doesn't fully consider the benefits of electric drive efficiency. Maybe ACEEE, in the spirit of promoting vehicle efficiency, should lighten up a bit on the weight penalty, at least until EVs roll out in greater numbers in 50 states.

The "Meanest"

Incidentally, there’s also a “Meanest” list, and the Ram 2500 (Class 2B) truck and Bugatti Veyron are close competitors there. The Ram gets an 18, and the Bugatti a 19. It’s hardly a surprise to see two Rolls-Royces there, the Phantom Drophead Coupe (23) and the Phantom EWB (also 23).

Here's the full "Greenest" list:


The "Greenest" cars on the market.

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