If all the hype is true, North America is about to see a rebirth in diesel-powered cars and trucks, bringing with it changes for plastics suppliers.
The clean diesels expected to hit U.S. showrooms at the start of 2008 will require new blends for the plastic housings on fuel pumps and other parts in close contact with the fuel, while some cars and trucks will have a second plastic tank on board to house the urea mixture used to cut nitrogen oxide emissions.
And while diesels may never take off as strongly in North America as they have in Europe - where they account for about half of all vehicles sales - automakers and their suppliers expect they will find a strong niche, especially with car buyers looking to get more miles out of each gallon of fuel.
``We're bullish on this,'' said Keith Price, a spokesman for Volkswagen AG's North American division. ``We're hoping that diesel is the new green.''
Volkswagen and DaimlerChrysler AG's Mercedes brand have been the main sellers of diesel-powered passenger cars in the U.S. during the past decade, bringing in cars originally designed for the European market, though those sales have been limited to a few models.
Nearly all the other diesels sold in the U.S. have been limited to heavy-duty pickup trucks.
There have been three major stumbling blocks to growth of the diesel market in North America: the low cost of gasoline in the U.S., which meant there was less demand for fuel-efficient vehicles; bad memories of the diesel engines of the 1970s and early 1980s; and a higher sulphur blend of diesel sold in the U.S. than was sold in Europe, which required automakers to alter their engines for top performance.
But with gasoline prices on the rise and a required change to a low-sulphur diesel in the U.S. last year that matched European standards, people are beginning to take a second look at the engines.
``People are learning that diesels today are not what they were before,'' said Jean-Bernard Lepage, innovation marketing manager for Paris-based Inergy Automotive Systems, a maker of fuel tanks and pipes. ``They're fun to drive.'' Lepage spoke in an interview at the Society of Automotive Engineers' World Congress in Detroit, held April 16-19.
The consulting group J.D. Power & Associates expects diesel sales for passenger vehicles in North America to climb from 543,000 vehicles this year to more than 1.1 million by 2011. That's still a small percentage compared to annual car sales of about 16 million, but a higher number than the predicted sale of 854,000 hybrid-power cars by 2011.
``We do believe that the business will move in North America to clean diesel, because of the energy savings,'' said Claude Mathieu, president of Mann+Hummel U.S.A Inc. The Portage, Mich.-based North American unit of Germany's Mann+Hummel GmbH makes filters and other parts for diesel engines.
But to sell in North America, carmakers must pass California's strict emissions control standards, and that means controlling nitrogen oxide - or NOX - which contributes to smog.
That is leading many automakers to a system called selective catalytic reduction, which uses a urea mixture to control tailpipe emissions. And that means business for companies, like Inergy, that are being called on to blow mold two tanks for each car - one for the fuel and one for the urea, which is marketed under the name AdBlue in Europe and already is being produced for commercial trucks.
Unlike the multilayer tanks needed for fuel, a urea tank is a monolayer high density polyethylene, but still has other issues, Lepage said. The carmakers and suppliers need to find space to fit the tank, which holds about 6.6 gallons of the liquid mixture. There is a separate heating element, so it works in cold temperatures, as well as filling pipes, sensors, a sending unit and other parts that have to be designed and integrated with the tank.
Inergy is preparing production now for a German automaker that will sell a 2009 model diesel-engine car in the U.S. next year using the urea system.
Not every automaker will opt for urea systems. Volkswagen's diesel-powered Jetta, which will go on sale in the U.S. in January, will meet the emissions standards in all 50 states without the tank, relying instead on an oxygenation catalyst and particulate filter, Price said.
But there still are issues that carmakers and suppliers must tackle for the U.S. market.
While the standard diesel fuel sold here matches European standard fuel, biodiesel does not. In Europe, a biodiesel blend is only 5 percent from a renewable resource, and always comes from rapeseed oil, said Rob Heiligenthal, manager of business development of the North American fuel systems division for Siemens VDO Automotive Corp. of Auburn Hills, Mich.
The U.S. biodiesel standard allows for a blend of up to 20 percent of the fuel coming from a biological source, and there is no standard on where that 20 percent will come from. It may be specially blended directly from the farm, or be reclaimed cooking oil using animal fats from a variety of different sources, he said.
``We can't control the acids that are being used,'' Heiligenthal said. ``Each material has its own problems. Plastics are attacked by the acids, which reduce their overall strength. In metals, there's a corrosive effective due to the acid reacting to the alloys.''
That is a big issue for Siemens, which makes plastic-encased fuel pumps and other parts typically housed inside the fuel tank.
``In North America, we also have an additional requirement that the materials be conductive because of concerns about static electricity,'' he said. ``We try to ground all of our plastic components by using conductive plastics, but there hasn't been a solution in the past that was both conductive and resistant to biodiesels.''
Siemens has been working with its resin suppliers to find the right acetal blend that can do both, he said, and is showing them to customers now with its biodiesel-ready products already on test vehicles.
``The industry really wants to be able to deliver a product like this,'' Heiligenthal said. ``It's a renewal product, and we're looking at solutions to help with the delivery of renewable fuels.''