To meet the new Emissions laws diesels can not run with the most efficient tune. With the most efficient tune it will produce too much NOx and too much sulfur. If you run the engine hot you get rid of the NOx but the sulfur goes through the roof. If you run it cooler you fix the sulfur but NOx goes sky high.
Right now there are two ways to meet the new standards. One is to run the engine cool and inject urea in the exhaust. Last I looked (a few months back) there were NO federal guidelines on how such a system would be employed in consumer vehicles, just "guidelines." They could easily changes the rules right now and systems already in-use would have to be changed.
The other option is to run the engines hot and put a DPF (Diesel Particulate Filter) in the exhaust. This introduces a restriction in the exhaust, the restriction drops the MPG a bit. The DPF collects the sulfur until it gets near-full. The ECU then injects fuel into the DPF to burn the contents off at a ridiculously high temp. This process takes care of both NOx and sulfur output but the MPG's take a hit. Both large and small diesel engines are using this method in the US right now.
In 2010 the emissions standards for ALL US diesels will become much more strict. MANY companies are concerned about not meeting the new standards. CAT is looking at withdrawing from the on-road Diesel segment entirely at the end of 2009 due to these new standards. It will be interesting to see what happens with consumer diesels with the new rules.
My '08 Volvo truck get about 1.5-2 MPG worse fuel milage than the same Volvo with a pre-2007 engine due to the DPF and required engine tune. figure 3000 miles per week in a vehicle that gets 6-7 MPG and that 1-2 MPG difference adds up FAST. I put $5-600 worth of fuel in my work truck every other day.
I would love to drive a 2.5L 4 cylinder common rail turbo diesel stripper(no-options) Mustang. It would be a hoot and get great fuel milage but the US market still isn't ready for a performance diesel car.
Consumer gas cars have engines that are MUCH more efficient than ever. The problem is that US consumers are demanding more power, more safety feature and more creature comforts in their cars. I don't have a problem with any of that, the market is meeting the consumers demands.
The problem is that almost all the new safety features add weight to the vehicle, as well as the creature comforts, without the vehicle getting physically larger. More power is needed to move all that extra weight. As the power output of the engines increase so does fuel consumption. This means that MPG's are increasing at a slower pace than they would be if all this extra crap wasn't needed/wanted. Consumers are just as big a part of the problem as the automakers.
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Right now my "fun" car is an '85 Mustang SVO that gets 26/33 City/Highway. My other vehicle is an '86 F-250 that gets 9-15 MPG depending on load/use. I run it on B20 during the winter and B99 in the summer. I do so little driving in my own vehicles that the last time I purchased fuel was September. Right now I need to put about 30 gallons in my pickup.
Right now there are two ways to meet the new standards. One is to run the engine cool and inject urea in the exhaust. Last I looked (a few months back) there were NO federal guidelines on how such a system would be employed in consumer vehicles, just "guidelines." They could easily changes the rules right now and systems already in-use would have to be changed.
The other option is to run the engines hot and put a DPF (Diesel Particulate Filter) in the exhaust. This introduces a restriction in the exhaust, the restriction drops the MPG a bit. The DPF collects the sulfur until it gets near-full. The ECU then injects fuel into the DPF to burn the contents off at a ridiculously high temp. This process takes care of both NOx and sulfur output but the MPG's take a hit. Both large and small diesel engines are using this method in the US right now.
In 2010 the emissions standards for ALL US diesels will become much more strict. MANY companies are concerned about not meeting the new standards. CAT is looking at withdrawing from the on-road Diesel segment entirely at the end of 2009 due to these new standards. It will be interesting to see what happens with consumer diesels with the new rules.
My '08 Volvo truck get about 1.5-2 MPG worse fuel milage than the same Volvo with a pre-2007 engine due to the DPF and required engine tune. figure 3000 miles per week in a vehicle that gets 6-7 MPG and that 1-2 MPG difference adds up FAST. I put $5-600 worth of fuel in my work truck every other day.
I would love to drive a 2.5L 4 cylinder common rail turbo diesel stripper(no-options) Mustang. It would be a hoot and get great fuel milage but the US market still isn't ready for a performance diesel car.
Consumer gas cars have engines that are MUCH more efficient than ever. The problem is that US consumers are demanding more power, more safety feature and more creature comforts in their cars. I don't have a problem with any of that, the market is meeting the consumers demands.
The problem is that almost all the new safety features add weight to the vehicle, as well as the creature comforts, without the vehicle getting physically larger. More power is needed to move all that extra weight. As the power output of the engines increase so does fuel consumption. This means that MPG's are increasing at a slower pace than they would be if all this extra crap wasn't needed/wanted. Consumers are just as big a part of the problem as the automakers.
------------------------------------
Right now my "fun" car is an '85 Mustang SVO that gets 26/33 City/Highway. My other vehicle is an '86 F-250 that gets 9-15 MPG depending on load/use. I run it on B20 during the winter and B99 in the summer. I do so little driving in my own vehicles that the last time I purchased fuel was September. Right now I need to put about 30 gallons in my pickup.
