The Cars.com Green Index monitors hybrid vehicle interest in the 50 largest markets in the country. These rankings are calculated based on the number of hybrid searches in a market as a percentage of all new-car searches in the market:

Market Percentage of Hybrid Searches

1) San Francisco/Oakland/San Jose 5.622

2) Portland, Ore. 4.784

3) Seattle 3.979

4) Sacramento, Calif. 3.973

5) San Diego 3.912

6) Los Angeles 3.504

7) Denver 3.394

8) Washington, D.C. 3.225

9) Minneapolis/St. Paul 3.188

10) Boston 3.174

11) Phoenix 3.163

12) Charlotte, N.C. 3.135

13) Raleigh/Durham, N.C. 3.098

14) Harrisburg, Pa. 2.811

15) Indianapolis 2.792

16) Hartford, Conn. 2.783

17) Salt Lake City 2.712

18) Louisville, Ky. 2.669

19) Las Vegas 2.625

20) Albuquerque/Santa Fe, N.M. 2.613

21) Kansas City, Mo. 2.610

22) Chicago 2.600

23) GreensboroWinston-Salem, N.C. 2.460

24) Nashville, Tenn. 2.427

25) Columbus, Ohio 2.389

26) Philadelphia 2.384

27) West Palm Beach, Fla. 2.349

28) Detroit 2.317

29) Greenville, SC 2.308

30) Milwaukee 2.307

31) Buffalo, N.Y. 2.307

32) Tampa/St. Petersburg, Fla. 2.302

33) Grand Rapids, Mich. 2.286

34) St. Louis 2.266

35) San Antonio, Texas 2.249

36) New York City 2.220

37) Orlando, Fla. 2.207

38) Cincinnati 2.202

39) Pittsburgh 2.148

40) Cleveland 2.148

41) Baltimore 2.089

42) Norfolk, Va. 2.081

43) Jacksonville , Fla. 2.000

44) Atlanta 1.995

45) Dallas/Fort Worth 1.960

46) Houston 1.937

47) Oklahoma City 1.913

48) Memphis, Tenn. 1.851

49) Birmingham, Ala. 1.844

50) Miami/Fort Lauderdale 1.829