The Greenest Cars of 2007 according to the ACEEE

The American Council for an Energy-Efficient Economy (ACEEE's) has created their Green Book Online for Model Year 2007 Vehicles. Three of the top four and four of the top seven are hybrids, including the Toyota Prius, Honda Civic Hybrid, Nissan Altima Hybrid and Toyota Camry Hybrid.

Make and Model	Specifications a	Emission Standard b	MPG: City	MPG: Hwy	Green Score
HONDA CIVIC GX	1.8L 4, auto [CNG] c	Tier 2 bin 2 / PZEV	28	39	57
TOYOTA PRIUS	1.5L 4, auto CVT	Tier 2 bin 3 / PZEV	60	51	55
HONDA CIVIC HYBRID	1.3L 4, auto CVT	Tier 2 bin 2 / PZEV	49	51	53
NISSAN ALTIMA HYBRID	2.5L 4, auto CVT	PZEV	42	36	48
TOYOTA YARIS	1.5L 4, manual	Tier 2 bin 5 / ULEV II	34	40	47
TOYOTA COROLLA	1.8L 4, manual	Tier 2 bin 5 / ULEV II	32	41	46
TOYOTA CAMRY HYBRID	2.4L 4, auto CVT	Tier 2 bin 3 / PZEV	40	38	46
HONDA FIT	1.5L 4, manual	Tier 2 bin 5 / LEV II	33	38	45
KIA RIO / RIO 5	1.6L 4, manual	Tier 2 bin 5 / ULEV II	32	35	45
HYUNDAI ACCENT	1.6L 4, manual	Tier 2 bin 5 / ULEV II	32	35	45
HYUNDAI ELANTRA	2.0L 4, auto	PZEV	28	36	45
HONDA CIVIC	1.8L 4, auto	Tier 2 bin 5 / ULEV II	30	40	44
[CNG] denotes compressed natural gas fuel. "auto CVT" denotes continuously variable automatic transmission. a Certain other configurations of these models (with different transmissions or meeting different emission standards) score nearly as well. b A listing with two emission standards (e.g., Tier 2 bin 2/ PZEV) denotes a single vehicle carrying both a Federal and California emission certification. Green Scores for such listings reflect the cleaner of the two certifications. c Compressed natural gas (CNG) vehicle fuel economy given in gasoline-equivalent miles per gallon.

According to their FAQ page, they rate vehicles based on their green scores:

We analyze automakers' test results for fuel economy and emissions as reported to the U.S. Environmental Protection Agency and the California Air Resources Board, along with other specifications reported by automakers. We estimate pollution from vehicle manufacturing, from the production and distribution of fuel and from vehicle tailpipes. We count air pollution, such as fine particles, nitrogen oxides, hydrocarbons and other pollutants according to the health problems caused by each pollutant. We then factor in greenhouse gases (such as carbon dioxide) and combine the emissions estimates into a Green Score that runs on a scale from 0 to 100. The top vehicles this year score a 57, the average is 30 and the worst gas-guzzlers score around 14. Further information can be found on the GreenerCars.com Methodology page.

The Honda Insight has fallen off the list (see the Greenest Cars of 2006), since it was discontinued, while the Nissan Altima Hybrid has joined the list when it debuted this year using Toyotas hybrid technology.

The ACEEE also has a Greener Choices of 2007 list that includes the Ford Escape Hybrid and Toyota Highlander Hybrid, which have a green score of 43 and 39, respectively. While not good enough to make the Greenest Cars list, they are the greenest choices in their segment. In other words, the ACEEE wants to "show that there are ways to buy a cleaner and more efficient vehicle throughout the market."