RASTATT, GERMANY — DaimlerChrysler sees a huge potential market for diesel-powered cars in the United States. Thomas Weber, the group’s head of research and technology and development head for Mercedes Car Group, said diesel motors’ performance, durability, and fuel efficiency could win converts from gasoline engines, especially once low-sulphur diesel fuel becomes widely available in the United States as of next year. Reducing the sulphur content in diesel fuel will allow advanced emission control technology in diesel engines and support substantially improved air quality. A study released last month by market research group J.D. Power-LMC Automotive Forecasting Services suggested U.S. sales of diesels were set to grow from 3 percent market share in 2004 to 7.5 percent by 2012, given high gasoline prices. However, tighter U.S. emissions standards and consumers’ perception of diesel engines as noisy and inefficient will be a limiting factor in their popularity. Of the 221,000 Mercedes cars sold in the United States last year, only 4,500 E-class models were diesel powered, which went on sale in April 2004.