The exhaust emissions of diesel vehicles could be given a clean-up boost from an unlikely source, as part of a wider bid to save up to 930 million gallons of fuel per year by 2030.
A diesel lobby is urging California to adopt diesel as part of a fuel economy drive, claiming the fuel is the greenest stepping stone to fuel cell vehicles of the future.
California carries weight with car manufacturers, not only for the size of its new car market, but also for its stringent emission rules for vehicles. With new car sales in excess of two million units per year, California would be the fourth largest market in Europe, and it contributes heavily to the 17-plus million new cars sold in the United States every year.
California also has by far the most stringent emissions controls of any US state – controls that to date have excluded diesel – which along with the cheap price of petrol, helps to explain the slow take-up of diesel. However, a growing American consciousness that dependency on fossil fuels is unsustainable, has put wind in the sails of the American pro-diesel lobby, and arguments are mounting that policy makers should switch their environmental focus from tailpipe pollutants such as oxides of nitrogen (NOx) and particulates (PM) to global warming gases such as carbon dioxide and fuel economy, areas where diesel performs strongly.
This could also prompt car makers to accelerate their plans to clean up the tailpipe emissions of diesel cars. A report unveiled last week at the US Department of Energy-sponsored Diesel Engine Emissions Reduction Conference estimated that if the diesel penetration of California matched European levels at 32%, the state could save 141 million gallons of fuel per year by 2010, and up to 930 million gallons per year by 2030.
Allen Schaeffer, executive director of the Diesel Technology Forum, said: 'Clean diesel technology is a proven, efficient and readily available solution for California's interest in reducing petroleum consumption.
'Other strategies such as fuel-cell vehicles are not commercially available and may take 15, 20 or even 25 years of research and development to reach the market. And even then these would not be as cost-effective as diesel or even use less net energy to produce.'
Diesel currently powers less than 2% of all cars in the US, and research by Fleet News found only the 7.3-litre Ford Excursion and Volkswagen Golf and Jetta available as diesel models in the US.
In Europe, diesel accounts for more than one-third of all new vehicles sales, and more than 70% of luxury and premium cars. The introduction of low-sulphur diesel in the US now makes the fuel a viable alternative in California, according to the report.
'Reducing California Petroleum Consumption with Increased Use of High Efficiency Clean Diesel Technology'. Existing and proposed California emission standards effectively discourage the production and sale of current technology light-duty diesel vehicles which have higher tailpipe emissions of NOx and PM, but also achieve greater fuel efficiency relative to gasoline engines, along with lower emission in reactive organic gases and carbon dioxide,' it said.
'New technology light diesel vehicles are likely to deliver much lower NOx and PM emissions in the near future in a manner that will not compromise air quality goals.'