Clean diesel vehicles made up half of the 10 highest scoring green cars in the Automobile Association of America's (AAA) Green Car Guide. The remainder included three electric vehicles and two hybrids.

"The field of green cars this year is the most competitive ever, so the fact that clean diesels ran away with five of the top 10 ratings is a great validation that clean diesel cars are really a great choice for consumers looking to make greener transportation choices," said Allen Schaeffer, executive director of the Diesel Technology Forum.

Two electric vehicles — the 2013 Tesla S P85 and 2012 Toyota RAV4 EV — topped the list. They were followed by four Audi TDI clean diesels (A6, A7, A8 and Q5) and the Mercedes-Benz E-250 BlueTEC clean diesel.

This year, AAA reviewed 83 hybrids, electric cars, CNG-powered cars, clean diesels and partial zero emissions vehicles for the guide. The annual study was conducted by the Automobile Club of Southern California’s Automotive Research Center (ARC). The green cars tested by the center are evaluated on the basis of 13 categories including emissions, fuel economy, acceleration, handling, and other factors.

Here's the full list:

1. 2013 Tesla S P85

2. 2012 Toyota RAV4 EV

3. 2014 Audi A7 TDI Quattro

4. 2013 Lexus GS 450h

5. 2013 Nissan LEAF

6. 2014 Honda Accord Hybrid

7. 2014 Audi Q5 TDI Quattro Tiptronic

8. 2014 Audi A8 L TDI Quattro Tiptronic

9. 2014 Mercedes-Benz E250 BlueTEC

10. 2014 Audi A6 TDI Quattro Tiptronic