Maintenance Execs Say Costs, DPF Service Are Top ’07 Issues
By Dan Leone, Staff Reporter
This story appears in the Feb. 11 print edition of Transport Topics.
ORLANDO, Fla. — Uncertainty about the life cycle of key emission control components and higher maintenance costs have emerged as the top concerns fleets have with 2007 heavy-duty diesel engines, maintenance and equipment heads at several major carriers said here.
The fleet executives, who spoke during a technical session at the 2008 annual meeting of American Trucking Associations’ Technology & Maintenance Council, also noted that emission control technology continued to depress fuel mileage, compared with vehicles manufactured before 2002.
Maintenance costs for 2007 model tractors “are about 28.2% higher” than pre-2002 engines, said Steve Duley, vice president of purchasing equipment for truckload carrier Schneider National. He added, “We don’t know the service interval for the [diesel particulate filters and] we don’t know the best way to service the DPF.”
Duley said his observations were based on a group of 48 2007 model-year Freightliner C120 tractors equipped with Detroit Diesel Corp.’s Series 60 engines that Schneider has had in regular service for about a year.
Dan Umphress, managing director of maintenance solutions for FedEx Freight, shared Duley’s concerns about diesel particulate filter service intervals.
Umphress estimated that the DPF in his carrier’s 2007 engines need to be cleaned every 200,000 miles, though none of the ’07 model tractors in FedEx Freight’s fleet have yet reached that milestone.
FedEx Freight, the less-than-truckload arm of Memphis, Tenn.-based FedEx Corp., runs about 1,000 2007 model-year tractors, Umphress said.
Tom Newby, director of field maintenance for Old Dominion Freight Line, also said it was “too early to tell on DPF concerns.”
Newby said the Thomasville, N.C., LTL hauler would look more closely at the maintenance needs of its fleet’s particulate filters in 2009.
Old Dominion runs several pre- and post-production 2007 tractors in its fleet of about 5,000 tractors. The single largest group of ’07 trucks has about 80 vehicles, Newby said. The company also has four pre-production ’07 tractors in its linehaul operations.
Particulate filters trap the soot produced by diesel engine combustion. The filters were added to many engines to help manufacturers bring their engines in line with the Environmental Protection Agency’s 2007 emission standard.
DPFs must be serviced periodically to prevent clogging, which could damage an engine, Duley said. The service interval for the filters is thought to be long — the panelists estimated hundreds of thousands of miles, though none had yet performed serious maintenance on their fleets’ DPFs.
Meanwhile, Duley said the 2007 engines were generally “reliable.” Schneider, Green Bay, Wis., had experienced most of its maintenance difficulties with emission control components such as exhaust-gas recirculation systems and DPF sensors.
Still, Duley estimated that Schneider’s 2007 trucks experience about 20% more downtime and visit the shop four to six times more than older models. Also, Schneider said it had to put its lead mechanics through about 25 hours to 40 hours of additional training to certify them to work on the ’07 engines.
FedEx Freight’s Umphress said the emission control systems of the ’07 engines were generally more reliable than those found in 2002 and 2004-model-year engines, but that the more complex aftertreatment systems in the ’07 engines required additional shop time and extended maintenance schedules.
“I’d say the downtime is comparable for all years,” Old Dominion’s Newby said, though he added that the 2007 trucks have given the carrier “a little more issues” than models from 2002 and 2004.
The panelists said the addition of increasingly sophisticated emissions technology continues to affect fuel economy, though in some cases, they noted improvements over the mileage rates of 2002 and 2004-model-year engines.
Umphress said that while mileage on FedEx Freight’s 2002 and 2004 trucks dropped about 16% compared with older models, the 2007 models were only about 3% less efficient than pre-2002 trucks.
Old Dominion’s Newby said his fleet’s 2007 tractors saw their mileage ratings drop to between 5.9 and 6.1 miles per gallon from the 6.4 to 6.8 miles per gallon the carrier had been seeing in 2002 and 2004 models.
Schneider’s Duley said the 2007 models burned even more fuel than their predecessors.
Duley estimated that a 2007 truck was about 5% less fuel efficient than pre-2002 models, costing the company about $2,800 per truck, per year in additional fuel expenses.
By comparison, Duley said 2004 tractors burned about 4% more fuel than pre-2002 models, and that 2002 models burned about 2% more fuel.
This story appears in the Feb. 11 print edition of Transport Topics.
ORLANDO, Fla. — Uncertainty about the life cycle of key emission control components and higher maintenance costs have emerged as the top concerns fleets have with 2007 heavy-duty diesel engines, maintenance and equipment heads at several major carriers said here.
The fleet executives, who spoke during a technical session at the 2008 annual meeting of American Trucking Associations’ Technology & Maintenance Council, also noted that emission control technology continued to depress fuel mileage, compared with vehicles manufactured before 2002.
Maintenance costs for 2007 model tractors “are about 28.2% higher” than pre-2002 engines, said Steve Duley, vice president of purchasing equipment for truckload carrier Schneider National. He added, “We don’t know the service interval for the [diesel particulate filters and] we don’t know the best way to service the DPF.”
Duley said his observations were based on a group of 48 2007 model-year Freightliner C120 tractors equipped with Detroit Diesel Corp.’s Series 60 engines that Schneider has had in regular service for about a year.
Dan Umphress, managing director of maintenance solutions for FedEx Freight, shared Duley’s concerns about diesel particulate filter service intervals.
Umphress estimated that the DPF in his carrier’s 2007 engines need to be cleaned every 200,000 miles, though none of the ’07 model tractors in FedEx Freight’s fleet have yet reached that milestone.
FedEx Freight, the less-than-truckload arm of Memphis, Tenn.-based FedEx Corp., runs about 1,000 2007 model-year tractors, Umphress said.
Tom Newby, director of field maintenance for Old Dominion Freight Line, also said it was “too early to tell on DPF concerns.”
Newby said the Thomasville, N.C., LTL hauler would look more closely at the maintenance needs of its fleet’s particulate filters in 2009.
Old Dominion runs several pre- and post-production 2007 tractors in its fleet of about 5,000 tractors. The single largest group of ’07 trucks has about 80 vehicles, Newby said. The company also has four pre-production ’07 tractors in its linehaul operations.
Particulate filters trap the soot produced by diesel engine combustion. The filters were added to many engines to help manufacturers bring their engines in line with the Environmental Protection Agency’s 2007 emission standard.
DPFs must be serviced periodically to prevent clogging, which could damage an engine, Duley said. The service interval for the filters is thought to be long — the panelists estimated hundreds of thousands of miles, though none had yet performed serious maintenance on their fleets’ DPFs.
Meanwhile, Duley said the 2007 engines were generally “reliable.” Schneider, Green Bay, Wis., had experienced most of its maintenance difficulties with emission control components such as exhaust-gas recirculation systems and DPF sensors.
Still, Duley estimated that Schneider’s 2007 trucks experience about 20% more downtime and visit the shop four to six times more than older models. Also, Schneider said it had to put its lead mechanics through about 25 hours to 40 hours of additional training to certify them to work on the ’07 engines.
FedEx Freight’s Umphress said the emission control systems of the ’07 engines were generally more reliable than those found in 2002 and 2004-model-year engines, but that the more complex aftertreatment systems in the ’07 engines required additional shop time and extended maintenance schedules.
“I’d say the downtime is comparable for all years,” Old Dominion’s Newby said, though he added that the 2007 trucks have given the carrier “a little more issues” than models from 2002 and 2004.
The panelists said the addition of increasingly sophisticated emissions technology continues to affect fuel economy, though in some cases, they noted improvements over the mileage rates of 2002 and 2004-model-year engines.
Umphress said that while mileage on FedEx Freight’s 2002 and 2004 trucks dropped about 16% compared with older models, the 2007 models were only about 3% less efficient than pre-2002 trucks.
Old Dominion’s Newby said his fleet’s 2007 tractors saw their mileage ratings drop to between 5.9 and 6.1 miles per gallon from the 6.4 to 6.8 miles per gallon the carrier had been seeing in 2002 and 2004 models.
Schneider’s Duley said the 2007 models burned even more fuel than their predecessors.
Duley estimated that a 2007 truck was about 5% less fuel efficient than pre-2002 models, costing the company about $2,800 per truck, per year in additional fuel expenses.
By comparison, Duley said 2004 tractors burned about 4% more fuel than pre-2002 models, and that 2002 models burned about 2% more fuel.
