According to Reuters, a Michigan congressman said he is preparing a bill to boost demand for diesel-powered cars and trucks through tax credits for oil companies and consumers. Reuters said such a move has long been favored by car makers, which see fuel-efficient diesel engines as a way to meet stricter fuel economy rules. Reuters said that, in Europe, where fuel taxes have helped promote diesel-powered vehicles, low-emission diesels account for roughly 40 percent of all new passenger vehicle sales but those diesels rely on low-sulphur fuel to meet clean-air requirements, and US petroleum refiners have sued to stop a federal mandate to produce low-sulphur fuel starting in 2006. According to Reuters, Democratic Representative John Dingell said, in a speech to a diesel technology forum in Washington, that he would propose a bill with tax credits for consumers who buy diesels that meet future emission rules. Reuters added that Dingell, the ranking Democrat on the House of Representatives Energy and Commerce Committee, said his bill would also require petroleum companies to produce diesel fuel with sulphur levels of less than 10 parts per million by 2009, just below the government's standard of 15 parts per million. The bill would give refiners tax credits to offset the extra cost of removing sulphur, as well as tax incentives to companies that meet the standard early, Reuters said.