Ford

Rob Stevens, chief engineer for commercial vehicles, said that while the fundamentals are the same for all of Ford's emissions systems, the actual hardware can be unique between offerings. Ford's medium-duty truck offerings will have Cummins engines and after-treatments and use hardware similar to the rest of the industry. The modifications allowed are determined by Cummins, and will be about the same for all truck manufacturers.

Ford's light trucks, up through Class 5, use distinct hardware to meet the 2010 emissions requirements.

On light trucks, an SCR chamber has been added to the diesel oxidation catalyst (DOC) and the DPF. Like the 2007 system, nothing in the after-treatment progression ahead of the last device can be modified without affecting certification.

The DEF dosing module is new, and can't be relocated or modified.

The DEF tank includes a supply module, temperature and level sensor, heated reservoir and splashing measures. The supply module recalls the DEF in the supply line when the vehicle is shut off.

The DEF is warmed, as required, to assure that it does not freeze during low ambient temperatures. The DEF spray pattern is optimized in the dosing module to promote mixing, improving the effectiveness of the SCR process. The exhaust sensors monitor the exhaust temperature throughout the process, along with the NOx levels and exhaust pressure. The engine-control modules work together with the various sensors and engine controls to assure compliance and perform system diagnostics.

Typical light-truck DEF tanks with mid-ship fuel tanks on pickups, vans, wagons and box deletes are coupled with the fuel tank to improve storage capacities. The completed-vehicle packages do not provide much opportunity for adaptation. DEF fill kits will be available for chassis cab and cutaway offerings, similar to fuel fill kits.

Typical light-truck DEF tanks for chassis cabs and cutaways are mounted outside of the frame on the right side of the vehicle. DEF fill will be located on the left side of the vehicle across the top of the frame, but can be relocated to the right side of the vehicle to best suit the second-unit body installation. Guidelines for tank relocation are being evaluated to accommodate line constraints.

Ford's light-truck DEF tanks are sized to meet EPA DEF replenishment guidelines, and tank capacities vary by model to meet this objective.

“Since DEF consumption is dependent on duty cycle and operator behavior, DEF replenishment may be required by the operator under some circumstances,” Stevens said. “DEF consumption is dependent on engine loads, because greater loads consume more DEF — both in terms of absolute consumption and relative to fuel consumption — and on driving conditions because steady operation consumes much less DEF than transient operations.”

Under normal operating conditions, the DEF should not require filling by the operator, per EPA replenishment guidance. For complete vehicles and related applications, the DEF tank and fill are located together, with the diesel fuel tank and fill on the driver's side.

The DEF warning system includes a series of audible warnings and cluster messages starting at 1,000 miles. Inducement of progressive performance degradations begin at “empty.” Similar warnings are used with the detection of unsatisfactory DEF.

Freightliner

Randy DeBortoli, project manager for 2010 emissions for Daimler Trucks North America, said the business class M2-106 and M2-106V have “switchback understep” vertical and horizontal systems. There is a clear back-of-cab solution with a six-gallon DEF tank and 50-gallon fuel tank, the lowest weight medium-duty after-treatment system, multiple available tailpipes and a clear right-hand PTO solution.

The daycabs' vertical tailpipes will have right- and left-hand B-pillars, while the horizontal tailpipes will have a short outlet and right- and left-hand turnouts. The extended cabs and crewcabs' vertical tailpipes will have right- and left-hand C-pillars, while the horizontal tailpipes will have a short back-of-cab (BOC) outlet and right- and left-hand turnouts.

“Although the location of the SCR and DPF systems are set, we will be publishing guidelines for exhaust tailpipe configurations to allow easier body-builder retrofit or modifications to meet our guidelines,” he said.

On the heavy-duty DV 13, a mid-chassis mounted one-box also will be available, housing both the DPF and SCR catalysts, and the mixing chamber for the DPF.