The biggest maintenance issues will be the time and cost of getting a truck or engine dealer to clean the DPF. Not only will the DPF, reportedly weighing as much as 300 pounds, require special handling equipment, but its cleaning will need to be done in a sophisticated vacuum chamber.
The Environmental Protection Agency mandates that the filter must go at least 150,000 miles before it needs cleaning. Manufacturers believe that in typical over-the-road driving, it’s likely to go much farther. Cummins’ Cyndi Nigh says units in linehaul service should “require service only once every four to five years.” The filters will be designed to last the life of the vehicle.
The Cummins ECM will monitor the performance of its Fleetguard DPF, and prognostics will indicate service intervals via the RoadRelay or Insite systems. This is likely to be an integral function of all onboard diagnostics anyway, since filters that are clogged with ash will increase engine backpressure, which interferes with airflow through the engine.
Cleaning will take one to two hours, and the labor charge will probably be the bulk of the cost. If your dealer’s hourly labor rate is $90, you’ll probably get out the door for $150 to $200, including a small fee for disposing of the ash. But the whole matter will likely be handled “when you come in for periodic maintenance,” Keene says. For those desiring quicker service, many outlets may offer exchange programs, simply switching your filter with one that has been cleaned.
The next potential maintenance issue is the closed crankcase system. Keene says the Caterpillar system “will be integral, with the gases passing through the DPF,” so DPF maintenance will take care of the crankcase system.
Cummins engines will use a simple filter manufactured by Fleetguard that will require annual replacement. At Volvo, “We don’t have any regular maintenance planned for the crankcase ventilation system,” Greszler says.
Another issue is lubricity of the fuel. Scrubbing out the sulfur removes some parts of the fuel that serve as lubricants for the injectors. Additives that improve fuel lubricity are abundant. Greszler reports that a lubricity requirement has been included in American Society for Testing and Materials specifications for the new fuel. This means that lubricity additives will be put in by the fuel suppliers, Cummins and Volvo say.
The manufacturers have already done a lot of fleet testing using the new low-sulfur fuel and the new lower-ash oils and have begun to determine change intervals. The reduced sulfur content helps reduce the need for TBN because crankcase acid is created when sulfur combines with oxygen. In most cases, drain intervals are expected to be the same as with current models or better, spokesmen say.
Nigh says 2007 engine longevity should be as good as ever. Stable architecture assures customers that the engine they are operating today will be the same basic engine in 2007 with the addition of exhaust aftertreatment. Cummins officials also are optimistic about having had more time to integrate their engines with truck systems than in 2002.
Volvo’s new engine is designed for higher cylinder pressures and will offer “enhanced durability,” Greszler says. The Series 60 design has also been “enhanced” in unspecified ways.
“With ACERT, Caterpillar is likely to have the lowest heat rejection of all the engine manufacturers,” Keene says. That would tend to help engine life and may also help reliability in other areas, for example the underhood hoses.
“We are already building 2007 C13 and C15 engines on the production line,” Keene says. “We are building and shipping a large quantity in the next two months.”