SCR, EGR, DEF, NOx, DPF and Sprinter engines
Sunday, January 17th, 2010If you want to get confused try figuring out what is going on with the Blue Tec diesel engines used in Sprinters.
Blue Tec is a brand, a name that Mercedes Benz markets emissions technology to reduce Nitrogen Oxides (NOx). It is used by several engines including some non-Mercedes. Under the Blue Tec brand are different technologies. One is the Selective Catalytic Reduction System (SCR) which reduces NOx and is used with DEF, a liquid made up of 32.5% urea which eliminates NOx. Yet another is Exhaust Gas Recirculation (EGR), used with Diesel Oxidation Catalyst and a Diesel Particulate Filter (DPF).
The 07-09 Sprinter engines used EGR with DPF and the 2010 Sprinter engine uses SCR and DEF. While the new engine has 185hp and 325 ft. lb. torque against the older (OM462) engine with 154hp and 280 ft. lb. torque. Don’t expect any better mileage in 2010 as the new engine and technology are actually years old in Europe which has stricter environmental standards than we have. We should have the European Sprinter engines but politics, NAFTA and other problems keep us running behind Europe.
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BlueTec SCR
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In-Cylinder Exhaust
Gas Recirculation (EGR) |
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Engine runs hotter, less efficiency lost to heat rejection. |
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Large loss of fuel efficiency due to additional recirculation of exhaust gasses. |
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Technology that has proven itself in real world testing in Europe over the past four years. |
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Unproven technology that is just a band-aid on 1970’s technology. |
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Up to 5% better fuel economy than EGR, and 3% more than today’s engines. |
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Loss of fuel efficiency when compared to today’s engines. |
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Reduces stress on many parts of the engine, thus lengthening engine life. |
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Can cause excessive wear on some engine parts thus shortening the life of your engine. |
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Needs only one DEF fill per |
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Necessitates regular active regenerations, which means more time spent on the side of the road, not earning. |
When you buy a 2010 Sprinter in the US you don’t have a lot of choices. You can chose only 1 engine. Someday we hope that changes.
But how does this technology really work?
In the EGR process (07-09 Sprinters), some of the exhaust gas is basically reburned to lower the emissions and the carbon particles from that process are caught in the Diesel Particulate Filter (DPF). The DPF is automatically cleaned at intervals by burning the particles in a process called regeneration.
In the SCR process (2010 Sprinters) Urea is injected into the exhaust gases from a Urea tank which has to be refilled by the driver just like the fuel tank at regular intervals.
For more information check the Sprinter Model Year 2010 Emissions Features. 
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