Mercedes-Benz presented three new SUVs equipped with the world’s latest and cleanest diesel engine at the 2008 New York International Auto Show. The new R 320 BlueTEC, ML 320 BlueTEC, and GL 320 BlueTEC use the highly efficient AdBlue exhaust aftertreatment system that meets the most stringent 50-state emissions limits.
Whether it’s the newly restyled ML320 BlueTEC family SUV, the larger GL320 BlueTEC or the versatile R320 BlueTEC, the diesel-powered Mercedes-Benz sport utilities get 20-30 percent better fuel economy, surprisingly good performance and extremely low exhaust emissions. This latest generation of electronically injected CDI engines is changing consumers’ dated perceptions about diesel engines. The BlueTEC diesels have impressive cruising range up to 600 miles traveling at highway speeds, and these well-appointed SUVs can do all that without sacrificing performance. In addition, V8-like pulling power makes the BlueTEC diesels ideal for towing.
BlueTEC is a modular system that includes an oxidation catalytic converter and a maintenance-free particulate filter as well as new techniques for reducing nitrogen oxide emissions – the last type of exhaust gas that’s higher in diesel vehicles than gasoline engines. The BlueTEC diesels use an NOx storage catalytic converter in combination with an SCR catalytic converter and AdBlue injection to lower NOx emissions.
The AdBlue system injects an aqueous urea solution into the exhaust flow, which releases ammonia (NH3), reducing nitrogen oxides to harmless nitrogen and water in the downstream SCR catalytic converter. Just the right amount of AdBlue for a given engine load and speed is injected to get the greatest reduction of nitrogen oxides. Its tank only needs to be refilled every 10,000 miles during routine maintenance intervals.