Back in the old days, exhaust was nothing more than a pipe, often with chrome, that went up the back of the cab. Then came diesel particulate filters in 2007 and selective catalytic reduction in 2010, with its additional diesel emissions fluid reservoir and pump. So, for most of the last decade, we’ve had multiple boxes on the chassis taking up space. For most, that represents three boxes (DPF, SCR, DEF). Daimler worked to combine the DPF and SCR into a single box in 2010 for their proprietary engine.
This week at NTEA, I heard Cummins announce a single box for the SCR/DPF for their new ISB engines and we can expect a similar combination for the heavy engines in the future. Mack announced a single box solution for the DPF/SCR as well. Mack’s ClearTech One also includes the dosing unit for the DEF, but does not look to include the DEF tank. Kenworth announced a clear back of cab solution for the DEF tank with a cutout in the cab.
These are significant improvements to the amount of chassis space taken by these devices. Since it also has less weight, it should be easier to manufacture. Those who have had to service the DPF, SCR, and DEF system will need to get their hands on these new designs, literally, to determine how easily they can be maintained. So, apparently, they put two heads together and figured out that one box is better.
