Officials with engine maker Cummins Inc. announced earlier this month that they are going to use the selective catalytic reduction after-treatment system in their heavy-duty engines beginning in 2010.
Even as late as September 2007, Cummins officials said the heavy-duty engine lineup would not be using SCR. Rather, the engine group announced it would not be using an aftertreatment system to reduce nitrogen oxide.
But, the evolution of catalyst technology led officials with the engine maker to opt for the SCR aftertreatment.
Cummins officials said in a mid-August announcement opting for SCR, that the decision to was driven by unprecedented fuel prices and the discovery of a new copper-zeolite catalyst material. The SCR systems require the use of a urea additive.