Towards a transatlantic diesel standard

By Pete Sweeney

Date: 24/03/05

Europe and the US have historically diverged in their different attitudes towards the environmental impact of diesel emissions. The Clean Air Task Force, an organisation sponsored jointly by the automobile industry and the US Environmental Protection Agency (EPA), released a report last month blaming 21,000 premature American deaths each year on diesel pollution. The EPA estimates that 65 million Americans live in areas where air quality violates federal standards, thanks in part to diesel emissions from heavy-duty engines used in industry, agriculture and mass transport.

"The EU standards for diesel emissions are a little more lenient than in the US," says Rich Cregar of the National Alternative Fuels Training Consortium at the University of West Virginia. The combination of high emissions standards and low standards of fuel has resulted in the near absence of passenger diesel cars from the US market. "Overall, the market in the US was not receptive to early diesel powertrains," says Adrian Schmitz, environmental and policy communications manager for Ford Europe. In 2004, 52% of new cars sold in Europe were diesels. In the US that number hovered around 3%. "But we believe clean diesels hold great promise," says Schmitz.

It now appears that harmonisation of transatlantic emissions standards is imminent. "I don't really see that there's a big disparity between the EU and the US," says Cregar. "The only issue is sulphur standards and that's been resolved. The US goes to the EU sulphur standard in September 2006."

Europe has traditionally been more intolerant of sulphur content in diesel fuel. While diesel fuel in Europe may contain up to 15 parts per million (ppm) of sulphur, the primary component in particulate pollution, US standards currently allow between 3,400ppm and 500ppm depending on engine type.

The EPA's acceptable cetane levels - another quality indicator of importance to diesel fuel - have not been harmonised with Europe. "Higher cetane numbers in the states may come about automatically through the conversion to ultra low sulphur fuel and the addition of biodiesel and/or cetane enhancers", says Cregar. "Yet if these improvements are not enough, further improvement in cetane would probably simply require a more expensive fuel as a result of further refining."

Industry experts unanimously cite "tremendous advances" in diesel technology, particularly 'common rail' systems, that are making the new diesel engines more efficient than even the new wave of hybrid fuel cars, which can only achieve their vaunted efficiency figures under specific driving conditions involving lots of starts and stops. In one EPA test, a diesel outperformed a hybrid's fuel economy by nearly ten miles per gallon. Diesel engines can also use 'biodiesel' fuels with little or no modification. Biodiesels are made from vegetable or animal fats yet share some 95% of diesel's energy efficiency without any petroleum-based polluting factors, including carbon dioxide emissions. Biodiesel's drawback - cold weather can cause it to gel - can be mitigated by mixing it in solution with low sulphur diesel. A recent collaboration between DaimlerChrysler, Volkwage, and Choren Industries has produced a product called 'SunDiesel' which they claim cuts carbon dioxide emissions by 90%. SunDiesel is produced from biomass and is therefore renewable. While biodiesel appears more immediately attainable than alternative energy sources like hydrogen fuel cells, producing economically viable quantities of biodiesel fuel presents a challenge and an opportunity for the agriculture sector. The US Congress recently agreed a $1/gallon excise tax credit for biodiesel to spur production.

The immediate challenge for European car manufacturers is the largely unexploited market for diesel passenger cars in the US. According to a report released by JD Power and Associates, a US-based marketing information services firm, the US market for diesel engines will increase to 10% by 2011. The same survey indicates that the total market for hybrid vehicles will grow to 3% in the same period. The US currently has no factories producing diesel engines for passenger cars. Once US diesel fuel standards align with European ones, European diesel engine manufacturers should be able to cross-market diesels in both markets. "Ford Motor Company and PSA Peugeot-Citroën are planning to expand production capacity," says Schmitz, citing "a high demand for [diesel] engines that will soon outstrip the existing supply base". As a result, Ford is adding production capacity for diesels at Dagenham in the UK by 2007, and at Volvo's Skövde engine plant in Sweden by 2006.

This opportunity may not come without local cost. Günter Verheugen, the commissioner for enterprise and industry, admitted to "substantial overcapacities in the mature EU market" in a recent speech on the auto industry. Some of this overcapacity is found in the traditional petrol engine manufacturing sector. The cost of converting such plants to diesel production appears to be prohibitive. Fiat and GM have struck a bargain to address the imbalance in diesel versus conventional fuel capacities; Fiat buys petrol engines from GM while GM buys Fiat's diesel engines.

But Fiat recently announced plans to close its Alfa Romeo plant in Arese, which produces conventional petrol engines. Thanks to the expense of retooling existing diesel plants, other industrialised nations already attracting investment from the automobile industry, notably in Latin America and Asia, are also positioned to compete for new investment. Cregar also claims some European manufacturers are eyeing the US. "As a matter of fact", he says, "some European manufacturers are considering expanding automobile production in the USA to offset currency losses due to the weak US dollar."

• Pete Sweeney is a freelance journalist based in Washington DC, United States.

Harmonisation of transatlantic emissions standards for diesel engines is now imminent and the immediate challenge for European car manufacturers is the largely unexploited market for diesel passenger cars in the United States.