Remeber, "green" car companies are not ranked like football teams.
You are talking about a
reputation... hence any snapshot you take has to be chronologically and geographically more broad than what you are looking at here. Look at the global picture over time, and the company does well.
It doesn't hurt that Honda has
consistently and
voluntarily made not insignificant contributions in the area of emissions and efficiency.
Honda innovated the CVCC engine in the 1970's, eliminating the need for a catalytic converter, when other car companies were vocally arguing that the emissions requirements could not be met.
In 1998, Honda introduced its first natural gas powered Civic, and today is the only company that markets a factory built CNG car directly to the public. (See
T. Boone Pickens, Jr.).
Honda introduced and
marketed in 1999, nine years ago, an aluminum-bodied, highly aerodynamic vehicle and uniquely, ingeniously and hybridly powered car.
There are other specific examples, but either way, Honda is a leader if not the leader.