Among Volkswagen's hottest-selling models are diesel-powered models that VW has been selling for years, given a new shot of popularity by rising gasoline prices, according to a May 15 story by David Kiley in USA Today. VW sold about 24,000 diesel-powered Golf, Jetta and New Beetle cars in the USA last year, about 8 percent of its total. The company has allotted about the same number for U.S. sales this year, but demand already is at about 12 percent of VW's total and growing. At that rate, the year's allotment could be gone by midyear, according to Kiley. In April, Golf TDI (for turbocharged direct injection) diesel sales were up 90 percent from a year earlier, compared with a 17 percent increase for total Golf sales. Jetta TDI sales were up 5 percent while total Jetta sales were even. And New Beetle TDI sales were up 5 percent while overall New Beetle sales were down 10 percent. VW is the only company selling diesel cars in the USA. General Motors, Ford Motor and Chrysler sell full-size diesel pickups, but they are bought mainly by contractors and trailer towers. Depending on the model, Volkswagen TDIs get 34 to 42 miles per gallon in the city and up to 50 on the highway. Making the vehicles more attractive is the fact that diesel fuel has been running about 25 percent cheaper than unleaded gas in most parts of the country. Volkswagen TDI buyers are following Europe's lead. About a third of all vehicles sold last year in Europe, where some drivers pay twice as much for gas as U.S. consumers, were diesels. This year, 40 percent of all sales are expected to be diesel. The disadvantage of diesel is that it is more polluting than gasoline. Its sulfur content currently is about 500 parts per million, although the Environmental Protection Agency has proposed requiring a reduction to just 15 ppm by 2006. Gasoline has an average of more than 300 ppm with a reduction to 30 ppm proposed by 2004. A car company must meet an EPA-imposed average corporate emissions limit. That means the average emissions level of all its vehicles combined must be below the limit or the company pays a fine. That keeps VW from selling more diesels in the USA because it would worsen its emissions average, according to USA Today.