US lawmakers press Japan on its auto clunkers plan

* U.S. lawmakers want more American cars to qualify

* Michigan Democrat says Japan has "rigged the rules"

WASHINGTON Feb 23 (Reuters) - A bipartisan group of 46 U.S. lawmakers urged Japan on Tuesday to allow more American cars to qualify for government subsidy payments under that country's "cash for clunkers" program.

The lawmakers, in a letter to Japanese Ambassador to the United States Ichiro Fujisaki, said steps previously announced by Tokyo to open its cash for clunkers program to more American cars fell short of what they expected.

"We are disappointed that Japan has unfortunately decided to use EPA (Environmental Protection Agency) city mileage ratings instead of EPA combined city/highway mileage ratings as the basis for determining eligibility," the lawmakers said.

Representative Gary Peters, a Michigan Democrat whose district is home to Chrysler's world headquarters and General Motors [GM.UL] plants, used blunter language.

"The Japanese continue to break their promise. They said they would allow American cars to participate in their cash for clunkers program but have rigged the rules so that few can," Peters said in a statement.

The program, which provides government cash to help people replace old cars, is intended to aid the environment while boosting the ailing car market.

Like the U.S. cash-for-clunkers program, cars in the Japanese plan must meet a minimum fuel mileage rating to qualify. More U.S. cars would meet that requirement if Japan used the combined city/highway rating.

Japanese officials say EPA's city ratings more closely match their own system for measuring fuel economy. But many in Congress find that explanation unconvincing.

"Our nation's open-market, free-trade policies and practices must have reciprocal application with our key global trading partners," the lawmakers said, reflecting complaints that Japan's market is generally closed to American cars.

During a trip last week to Detroit, U.S. Trade Representative Ron Kirk also expressed concern about Japan's cash for clunkers program and said "more can and should be done" to open the program to American cars.

The letter to Japan's ambassador came as Toyota Motor Corp (7203.T) (TM.N) President Akio Toyoda was in Washington to testify on safety problems that led to the company's recall of more than 6 million cars in the U.S. market.

(Reporting by Doug Palmer; Editing by Eric Beech)