well ive been doing some more reading on that urea stuff and from what i've found it looks like it will cost between $3 and $9 per gallon (depending where you buy it)and i've read that the super duty will hold between 8 to 12 gallons of urea. so thats as much as $36 or $108 to fill up every 7k miles.
Then you've heard wrong. The urea tank is 5 gallons. It is expected to be topped off (not totally refilled) at each oil change. The expected mileage is 7,000 to 12,000 miles per 5 gallons depending upon how the vehicle is used. Urea is currently available in 1 gallon, 2.5 gallon, 5 gallon, and 55 gallon size containers.
The use of urea with a diesel is nothing new. Diesel cars and trucks in Europe have used urea for the past several years. The BMW diesel and Mercedes diesel cars imported into the U.S. all use urea. A number of heavy duty diesel motor manufacturers currently use DEF for their motors - Cummins still does not.
Most of the diesel exhaust fluid (DEF) is manufactured and distributed by
Tera Environmental Technologies (TET). DEF reduces nitrogen oxides (NOx) as it is a catalyst.
On the Dodge pickups, Cummins uses "super EGR" which is more gas recirculation, higher turbo boost pressures, and higher fuel injection pressures. There is also a close-coupled catalyst (CCC) mounted after the turbine. A small amount of fuel is sprayed into the CCC and chemically oxidized. As this happens the exhaust temperature increases allowing the downstream catalytic converter to work more effectively.
There are pros and cons with both systems. The problem with the super EGR approach is that it reduces the air to fuel ratio, and that, plus the use of the CCC, may reduce fuel mileage. An example of the air / fuel ratio change comparing a 1998 motor to the 2010 - the air / fuel ratio for the 1998 Cummins was 28:1 and in the new motor it will be 20:1.
