I pulled this from an online magazine. I did not see a copyright notice. Thought some of you would like to read it.DETROIT -- General Motors plans a series of expensive changes to its Duramax V-8 engine to cope with tough U.S. diesel emission rules taking effect Jan. 1.GM says reworking the 6.6-liter diesel, which powers heavy-duty versions of the Chevrolet Silverado and GMC Sierra pickups, won't interrupt production. But the modifications are expected to sharply increase the cost of building the engine.Heavy-duty trucks with a gross vehicle weight rating of as much as 10,000 pounds must meet the Tier 2 Bin 5 emissions standards. The new rules call for a 90 percent reduction of oxides of nitrogen, or NOx, and particulate matter, or soot.GM will significantly revamp the emissions system of the Duramax, which also is used in full-sized vans and commercial vehicles. GM Powertrain spokeswoman Susan Garavaglia said the diesel will meet the 2007 regulations with:>> A new variable geometry turbocharger.>> Enhanced exhaust gas recirculation.>> Closed crankcase ventilation system.>> Changes to the exhaust system that include an oxidizing catalytic converter to clean NOx emissions and a particulate filter to lower soot.Diesel particulate filters, first used in Europe in 2005 on Peugeot and Citroen vehicles, will land in America for the first time on diesel versions of the Mercedes-Benz E320 and the Jeep Grand Cherokee coming this fall.The new Duramax developed to meet the emissions regulation won't be available until Jan. 1.GM's upgrades won't be cheap. The particulate filter and oxidizing catalytic converter, for example, could add at least $3,000 to the cost of building the truck. The estimate is based on hardware costs for older diesels that have been retrofitted with filters and related equipment. GM won't confirm the figures. Demand is strong for GM's diesel trucks. Capacity from the lone Moraine, Ohio, plant that builds the engine is limited to about 180,000 units a year. Because the Duramax has built a reputation for being smooth, quiet and reliable, GM sells out of diesel trucks each year and gets close to sticker prices, which start at about $30,000 and can go as high as $50,000.GM's technical solutions differ from what sources say Ford Motor Co., Volkswagen and DaimlerChrysler plan for diesel powerplants in the United States. Ford will launch a revamped Power Stroke diesel truck engine in the first quarter of 2007 that uses piezoelectric fuel injectors. Piezo injectors enable an engine to run cleaner by producing less NOx in the combustion chamber. Particulate filters reduce NOx in the exhaust system.Chrysler group officials won't comment on what changes the Dodge Ram diesel will get for the 2007 model year. But spokesman Nick Cappa said that Mercedes-Benz's Bluetec diesel emissions system, a suite of technologies that includes traps and filters and urea injection -- also will be used on Chrysler group vehicles. Urea systems shoot an ammonialike acid into the exhaust pipes, radically reducing NOx.At least two automakers are pulling diesel vehicles out of the United States until they can meet the new standard. The Chrysler group ended production of the Jeep Liberty diesel May 31, even though the small SUV has surpassed sales expectations. The Liberty could be back with a cleaner diesel engine in 2008 when it gets a face-lift and is re-engineered, sources say. Volkswagen plans to build up an inventory of about 10,000 diesel Jettas between now and Dec. 31 and sell leftover 2006 models while it retools its diesel fuel injection system. The 2006 Jetta and the Touareg SUV will be the only VW diesels in the lineup in 2007.