Truck OEMs serving the refuse industry are taking a myriad of approaches to meeting the ’07 emission regulations that result in significant operating differences among their products.
For example, Autocar LLC has barred active regeneration of the diesel particulate filter (DPF) on its trucks from occurring below speeds of 20 mph and does not give drivers a manual override switch to ‘turn off’ the active regeneration process. Mack Trucks, however, did the opposite— providing a manual override switch for drivers to shut off active DPF regeneration at their discretion.
“It just gives drivers an option,” Steven Ginter, vocational product manager for Mack, told FleetOwner at Waste Expo this week in Atlanta. “The truck still operates just fine during active regeneration, which usually takes about 20 minutes to complete and roughly occurs once or twice a day at most. But we wanted to give them the flexibility to shut it off depending on their location.”
At issue is the higher exhaust temperatures produced by the active regeneration process. Ginter said Mack’s exhaust-end temperatures top 1,050 degree Fahrenheit during active regeneration, which is cut down by 200 to 250 degrees through the use of a “diffuser” on the exhaust stack. This device mixes cooler ambient air into the exhaust pipe to cut down that exhaust heat.
Tom Vatter, vp-sales and marketing for Autocar, told FleetOwner their exhaust-end temperatures are higher– about 1,400 degrees F– and so wanted to give drivers peace of mind by blocking active regeneration completely during the typical stop-and-go refuse truck operating pattern.
“That way, the driver doesn’t need to worry about active regeneration at all,” he explained. “If the truck is under 20 mph, it won’t occur. No additional driver inputs are necessary.” Vatter noted that this method has performed well in the four Autocar ’07 test trucks that have been on the road since last year– one in Georgia, one in Ohio, and two in California.
Ray Paradis, director of vocational markets for Peterbilt Motors Co. told FleetOwner that the real challenge is convincing customers that ’07 technology isn’t overly complex. He’s been taking six demonstration trucks across the country to conduct what he terms “show and tell” events with customers to get them comfortable with the technology.
“Once they see it operate, it really isn’t that big a deal anymore,” he explained. “Yes, it still makes trucks more costly, but the worry about how the technology works added to their worries. That’s one reason we’ve seen sales drop in the first and second quarters this year. Once they get more comfortable with the technology, I think you’ll see sales rise again in the third and fourth quarter.”
Another issue, added David McKenna, Mack’s powertain sales and marketing manager, is listening to what OEMs have learned from their extensive testing of ’07-compliant trucks, as they’ve gained some important maintenance insights.
“By mandate, DPFs must go a minimum of 150,000 miles before they need to be cleaned,” he told FleetOwner. “That translates into roughly 4,500 hours for vocational operators. Now, they need to use the new CJ-4 oil with these new engines, but we’ve found another benefit to using it: it vastly extends the DPF cleaning interval. So we are encouraging fleets to make sure they use CJ-4 in their ’07 engines as they are going to get much longer filter life by doing so. That will save them money over the life cycle of the vehicle.”
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