Green car owners have apparently complained in such large numbers that the Honda Civic Hybrid isn’t living up to high mileage claims that the carmaker has approached U.S. government regulators about revising its mileage guidelines, according to a lawsuit by one Honda hybrid owner.

A California appellate opinion filed on Monday showed that a Honda customer service representative told Gaetano Paduano, the dissatisfied owner of a 2004 Honda hybrid, that the company had received “a high number of complaints” that the sedan achieves significantly less than its promised mileage of 47-plus miles per gallon.

The rep also told Paduano that the company and rival Toyota have approached the U.S. EPA to change the mileage rating on their hybrid cars, the opinion said.

Another Honda rep told Paduano that he probably couldn’t achieve the advertised mileage by driving the vehicle like a conventional car, despite claims to the contrary in a Honda brochure advertising the vehicle, the opinion said.

A Honda spokesman would not comment on the pending litigation.

Paduano’s lawsuit, filed in 2005, follows at least one other legal action over low mileage complaints for the Honda Civic Hybrid, the other filed in U.S. District Court and decided last year.

The San Diego based appeals court ruled that Paduano can go ahead with his false advertising lawsuit against Honda in a California state court.