Some customers have expressed concern about adding another fluid. "You need to buy an extra tank of product - diesel exhaust fluid," says Kaufman. "Based on a 100,000 mile a year application, you are talking less than $300 a year in consumption. If you take a conservative 3% improvement in fuel economy at today's fuel prices, the return is pretty easy to see. Diesel today is at an average $3.09. Do you really think it is going to stay there? Over the life of the vehicle, it certainly makes sense to me that this is the right solution."
Despite being relatively new to the U.S., Europe and Japan have a proven track record with SCR technology.
Ford has also reduced maintenance costs by extending transmission fluid drain intervals to 150,000 miles. A dual filter provides fine filtration and large capacity in a single package, and eliminates the need for an external spin-on filter.
Ram Trucks chassis cabs also use SCR. "The Cummins turbo diesel engine uses a commercial-grade SCR system to reduce oxides of nitrogen (NOx) by as much as 83% in order to meet the new, more stringent 2010 diesel emissions requirements," says Dave Elshoff, head of Ram Truck brand communications, Chrysler Group. In addition, the company offers savings on maintenance with 7,500-mile standard oil change intervals.
Many of the diesel-equipped chassis cabs offer an exhaust brake, including the Ram 3500, 4500 and 5500 chassis cab vehicles, on which it's standard. "This feature reduces brake fade, prolongs brake life and provides confidence and safety when hauling heavy loads," notes Elshoff.
Pay attention to which features come standard and which are options. For instance, according to Elshoff, Ram has added a number of no-cost standard content to the all-new chassis cab, including power windows, locks and mirrors.
Also look at features unique to each vehicle make. Take Ford's live-drive PTO on its TorqShift transmission. The PTO output gear is linked through the torque converter to the engine crankshaft. This allows the transmission to power auxiliary equipment with up to 50 hp and 250 lb.-ft. of torque output. The power is available any time the engine is running.
Previously, if you wanted a live-drive PTO, you had to install a clutch pump that would operate hydraulics off the front of the engine. "It was very expensive," says Kaufman. "It required a significant amount of time and labor to install it. Now, with the live-drive PTO, it is real simple. It is relatively low cost compared to a clutch pump. It is easy to service and install.
General Motors chose to use an independent front suspension in its Chevrolet and GMC chassis cabs vs. a solid front axle like its competitors. "But we beefed it up significantly," says Tigges. "We have a 6,000-lb. maximum gross axle weight rating. And by going with that independent front suspension, we are able to provide better ride and handling than with the solid axle. There is a lot less unsprung weight, a lot less weight that is not riding on the springs. You don't have to control all of that weight going up and down. You keep more tire on the road."
All of the chassis cabs are available with automatic transmissions that can manually limit the highest available transmission gear, and allow manual upshifts and downshifts based on road speed and engine speed for improved towing. "However, the Ram chassis cab is the only vehicle in its segment to offer a manual six-speed transmission, standard on all diesel models," Elshoff asserts.
In addition, there are unique features offered by each manufacturer that increase upfitter friendliness. For example, Ram Truck chassis cabs feature four upfitter switches integrated on the instrument panel. "Each of these four upfitter switches are linked to an auxiliary Power Distribution Center (PDC) located under the hood, which includes one fused 20-amp battery feed and one fused relay-controlled 20-amp ignition," says Elshoff. "In addition to these feeds, the PDC supports four new customizable switches. Two switches are ignition fed and the remaining two are either battery or ignition."
Another upfitter feature is the ability to handle auxiliary-fueled equipment. "A special capped auxiliary fuel line on the fuel tank makes upfitting even easier, facilitating the use of auxiliary equipment running on fuel," Elshoff states.