How will EPA 2010 emissions control systems affect vocational truck body builders? That question brought forth a panel of OEM experts at the recent National Truck Equipment Association (NTEA) Work Truck Show in Chicago.
The seminar, entitiled "Upfitting Equipment on 2010 Emission Compliant Truck Chassis," included representatives from several OEMs, who discussed new challenges in body and equipment mounting, location of Diesel Exhaust Fluid (DEF) tanks, maintaining emissions compliance, additional engine cooling concerns, increased vehicle complexity, and increased curb weight.
Bottom line: chassis are going to become more crowded in 2010, and body builders will not be allowed to modify or relocate any of the components of the new emissions systems. Because of that, OEMs are bending over backwards to provide clear back-of-cab solutions.
END-USER ISSUES
The Selective Catalytic Reduction (SCR) emissions systems that will be on every 2010 diesel from Cummins, Detroit Diesel, Fuso, GM, Hino, Isuzu, Mack, UD and Volvo consists of the DEF tank (with its fill spout and cap), feed lines leading to the pump and to the DEF injector, and then the SCR control module and the SCR catalyst itself.
Each OEM representative layed out in detail where these components will be located, how much space they will take up, and how much the complete systems will weigh, all of which will affect design and installation of work bodies and accessories. What may have been of greater interest to the end-users in the audience, however, was the information about exactly how the new systems will operate, and what impact they will have on day-to-day operations and driver behavior.
Bearing in mind that an SCR-equipped diesel engine cannot be allowed to operate without DEF, the 2010 Dodge Sprinter van and chassis-cab, for example, will have a dash display that lights up to warn the driver when he is down to his last 1.5 gallons (out of a 6.6 or 7.4 gallon tank) of the fluid. If the level continues down to 0.8 gallons, the driver receives both a visual and an audible warning, and will be limited to only 20 engine starts. If both warnings are ignored, the driver's 20th engine start will be his or her last until at least two gallons of DEF are added to the tank.
As you can see, this is nothing to fool around with...
COLD STARTS
Because DEF becomes a frozen slush at 12 degrees F, it must be kept warm. Each OEM has its own strategy for heating its DEF tanks and lines, but they have one feature in common: whenever a truck with a DEF system is shut off, the pump draws all DEF back from the lines and into the tank, to prevent line freeze-ups. Of course, DEF can't be kept heated when the truck is shut off, so what happens in a cold start situation? Because a cold engine doesn't emit NOx in great quantities, the Environmental Protection Agency allows a grace period of several minutes in cold-start situations for the DEF tank to be warmed up and for the fluid to begin flowing to the injector.
Depending on which truck you purchase, your DEF filling spout could be under the hood, right next to the diesel fuel fill cap, or someplace else entirely. Hearkening back to when unleaded fuel was introduced in the 1970s, DEF nozzles will be smaller than diesel fuel nozzles, making it impossible to pump fuel into the DEF tank.
It's difficult to say with accuracy how much DEF any particular truck will consume, since consumption will depend in some degree on duty cycle and engine load. But if you want to stock your own DEF, the fluid will be available for order in a variety of sizes and configurations, including one gallon and two-and-a-half gallon jugs, 55-gallon drums and 275 gallon totes.
The cost of DEF is still subject to speculation. The NTEA projects that DEF could cost $2.50 a gallon or higher, although how much higher is anyone's guess.
OPERATIONAL MATTERS
But, as we've already seen, running without DEF is not an option. The Sprinter's solution may seem extreme, but other 2010 trucks will be programmed to depower if the DEF level becomes perilously low. After ample warnings, and only with clear evidence of safe driving conditions--after the engine has been shut off and restarted, or the diesel tank has been refilled without an increase in DEF level, or the vehicle has been stationary for over an hour--vehicle speed will be limited to five mph until the DEF is refilled. Under no circumstances will a 2010 SCR truck engine be shut down during operation.
The NTEA presenters answered a great many questions, and undoubtedly raised many more. When more answers appear, you'll read about them here in Fleet Maintenance.
