Taking the confusion out of BLUETEC diesel technology

Ask the Mechanic
By: Eric Allen
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If you've been driving around lately and seen a new Dodge Cummins diesel pickup truck with the unfamiliar BLUETEC DIESEL emblem on the back, you're probably saying to yourself, What's that mean? Well, let me bring you up to speed and give a little info so you can understand what it's all about. There are some of us who think heavy-duty diesel pickup trucks and passenger cars are smoky, stinky, loud and just downright obnoxious when we find ourselves stuck next to one at a stoplight or in the supermarket parking lot. Well, that's all changing with the introduction of BLUETEC-equipped Dodge Cummins diesel trucks and the new Jeep Grand Cherokee common rail diesel (CRD). These vehicles come equipped with emission packages that provide full compliance with 2007 Environmental Protection Agency (EPA) and California Air Resources Board (CARB) exhaust emission requirements. Let's start by answering a few questions. What is BLUETEC? BLUETEC is a host of DaimlerChrysler technologies for diesel passenger vehicles, beginning with completely modern, efficient diesel engines. BLUETEC may also include an oxidizing catalytic converter, a diesel particulate filter and an innovative system for reducing nitrogen-oxide emissions ” a selective catalytic reduction (SCR) technology. Selective catalytic reduction is an exhaust gas treatment system that converts nitrogen oxides into nitrogen and water vapor by adding ammonia as a reducing agent in a catalytic converter. These technologies can be used in various combinations depending on the specific needs of the vehicle. Ok, so what does that mean to me if I am considering buying a new Cummins-equipped Dodge pickup or Jeep Grand Cherokee (CRD)? It means that your vehicle meets or exceeds emission requirements for 2010. The Cummins 6.7-liter, high-pressure common rail (HPCR) engine used in the 2007 and '08 model year Ram trucks is considered the cleanest-burning heavy-duty diesel engine in North America. Diesel emission requirements have changed significantly, both oxides of nitrogen (Nox) and particulate matter (PM) emission requirements have been reduced by 90 percent from 2004 levels. Crankcase gases are also included in the emissions measurements, so the use of a closed crankcase ventilation system is standard. These engines also require the use of ultra low sulfur diesel fuel to maintain these emission standards. What is the deal with ultra low sulfur diesel fuel? Ultra low sulfur diesel fuel is a new fuel standard that has been phased in since 2006. It contains 15 parts per million sulfur content maximum. This fuel has several beneficial effects. Because it produces less particulate matter from combustion, it enables oxides of nitrogen absorber technology to be highly effective and reduces the production of sulfuric acid. If you were to run just low sulfur diesel or non-highway diesel fuel, this system would begin to fail as the sulfur content would be so high that it begin to clog the aftertreament components as they try to regenerate or burn off the excess particulate matter. Remember, use ultra low sulfur diesel only in these engines. So, BLUETEC is a more efficient, quieter, and cleaner-burning diesel engine that meets or exceeds emission requirements for 2010 standards. Eric Allen is the shop foreman for Magnussen's Dodge Chrysler Jeep at 1901 Highway 49 in Auburn. He can be reached at (530) 885-2900.