Many people familiar with the dramatic changes taking place in work trucks powered by diesel engines are groaning, grumbling and complaining about what those changes are doing to their businesses. Federal air-quality regulations for new highway trucks, the latest round in effect since January, are driving engine manufacturers to add on complex emissions reduction and electrical systems that also must protect power, torque and fuel economy. What’s more, petroleum companies are reformulating lubricants to match the new engines’ needs and truck manufacturers, dealers and body fitters also are working to offset the added repair and component costs of these vehicles with ancillary features to make the complete package worthwhile for construction end-users.

PLUGGED Hard-wired truck hookups are less expensive than wireless ones but limit mobility.

The added costs are clear, but some of the benefits to the owners have yet to be seen. And the changes coming all at once seem like enough chaos to make a construction mechanic blow a head gasket.

Equipment and maintenance costs are increasing for new engines that have little experience on the road. "We are constantly chasing our own tail," says Brian Jacoby, field engineering district manager for Castrol Heavy Duty Lubricants, Baltimore.

As with cars over the past 35 years, emissions controls are the main technology drivers on work trucks today (ENR 3/17/03 p. 26). While the engines run cleaner, analysts say there is a general uncertainty about how the new diesel engines will perform in the long run, which could threaten the market share of work truck producers. In construction, these vehicles encompass the entire trucking spectrum from light-duty pickups to Class 8 tractor-trailers.


For diesel engine manufacturers, in particular, 2004 will be the big test for their respective emissions technology and set the tone for how well they will meet future regulatory requirements without compromising engine life and performance. "Longevity is a concern," says William T. Vanden Brook, motor vehicle superintendent for the City of Madison, Wis.

There also is much heated activity behind the scenes as construction equipment technicians try to learn about the care and feeding of the new equipment. In the field and in the shop, they are moving fast to acquaint themselves with the new engine technologies and the individual preventive maintenance issues, a daunting, time-consuming and costly effort. It promises few returns–except added job security. "Everybody now has got to make it or break it," says Rodney Lilly, service manager at Navistar and Kenworth dealer Roberts Truck Center, Amarillo, Texas.

Although initial reviews are very mixed, one benefit of cleaner diesels that technicians can agree on is easier diagnostic capability due to built-in electronic sophistication. "If there is one thing that’s really different, it’s that you are going to see a lot of laptops and computers in the shop," says Leland Redding, chair of Texas State Technical College’s diesel training program in Waco. His institution trains diesel mechanics in 10 separate, 20-month degree programs that cost between $4,500 and $7,000. "All the technology is now being applied to transmissions, brakes and creature comforts [and] a truck could have multiple computers on it," he says.

Efficiency tools, like laptops, PDAs, specialized software and wireless computer-to-engine connections have arrived in the hands of diesel engine mechanics. With diagnostic software specific to each manufacturer, computer outfits can cost thousands of dollars and require regular software upgrades.

But there are noteworthy benefits that come with these tools. Mike Monnot, Zachry Construction Corp. equipment director in San Antonio, says that in the past, "most large contractors had people who specialized in engine repair, transmission repair and hydraulic repair," but that is changing. Having trucks with hard-wired electronic monitors "reduces your overall maintenance manpower and expedites the diagnostic portion of your troubleshooting," he says.

Truck manufacturers are touting the features of what they call electronic "multiplex" systems–on-board component monitors and diagnostic indicators. Late last year, medium-duty producer International Truck and Engine Corp., a Navistar company based in Warrenville, Ill., introduced the work truck market’s latest effort in CAN-bus technology, a type of mobile electronic-control system that is lighter on wiring harnesses than predecessor technology.

Now common on cars, light-duty pickups and some heavy construction equipment, CAN-bus connections integrate a centrally located, on-board computer that controls every function on the vehicle, from engine idle speed, to airbag deployment, to the little light in the glovebox. The main unit wields control over smaller "slave" modules placed at various locations around the chassis.

"One of the reasons we decided to do a multiplexing system is a high turnover in drivers...and also speed of diagnostics," says Scotty Hepler, an International application engineer. The company’s new "Diamond Logic" control system allows users to customize switches in the cab as well as diagnose problems with a $550 hard-wired cable or $750 wireless hookup for laptops. The wireless connection has a 300-ft range, which lets technicians check trucks for preventive maintenance with little or no movement, according to Hepler. "We just started getting into [wireless]. It’s more of a convenience thing," says Lilly.

With emissions reduction still the objective, these new electrical systems work in concert with engine functions, which now rely on computers for precision timing and cleaner burns. That story is the same for all diesels, but how the manufacturers deal with exhaust cleanup is the biggest technical difference. "I guess we’ll learn as we go," says Terry Howard, equipment operations director for pipeline contractor ASRC Energy Services, Anchorage. Click here to view chart

The most recent emissions standard took effect in January, but most engine makers had to pull ahead to meet an October 2002 deadline under a consent decree that Caterpillar, Cummins, Detroit Diesel, Volvo, Renault, Mack and Navistar International signed with the U.S. Environmental Protection Agency in 1998. Most engine firms, including Cummins, Detroit Diesel, Volvo (which acquired Renault and Mack in 2001) and Navistar now are using cooled exhaust-gas recirculation (EGR) to meet the highway standard of 2.5 grams per brake-horsepower-hour of combined nitrogen oxides and non-methane hydrocarbons.

EGR grabs exhaust as it leaves the engine, cools it down with a larger radiator than before and reintroduces exhaust back into the combustion cylinder where it mixes with fresh air. This makes the cylinder operate much hotter than before, as much as 15°F on average.

International, also involved in the consent decree but under different terms than the other manufacturers, publicly unveiled its 2004 EPA-compliant, cooled-EGR engine at the World of Concrete show, held Feb. 17-20 in Orlando (see p. 14). "Most of the benefits are emissions-related," says Gregory J. Saele, product manager.

Caterpillar and Mack have stood out from the crowd with their new engines. Cat made the biggest stir with fleet owners last March when it unveiled its Advanced Combustion Emissions Reduction Technology, or ACERT for short. It was six months late to arrive but its engineers claim that its integrated approach of double-turbocharged air delivery, computer-timed fuel injection and exhaust after-treatment will help Cat meet 2007 mandates with little effort.

Even though Mack is using cooled-EGR for its freight-carrier engines, it has designed a separate "internal EGR" technology exclusive to its line of work trucks. Rather than cooling down exhaust and piping it back into the cylinder, an internal EGR system cracks open the exhaust valve during the intake stroke, according to David McKenna, Mack product manager in Hagerstown, Md. He says there are approximately 14,000 of these engines in the field.

Without question, the engine market is getting extremely competitive. Caterpillar, Cummins, Detroit Diesel and Mack held respective market shares of about 33.8%, 20.5%, 16.6% and 10.4% in the domestic Class-8 diesel engine market last year. Development already is under way for these manufacturers to meet a January 2007 EPA mandate. Despite the "perceived differences" between all these systems, the upcoming regulations to reduce NOx to 0.2 g/bhp-hr and fine particulate to 0.01 g/bhp-hr will be achievable with the current methods, according to Stephen Haggerty, New York City-based machinery analyst for Merrill Lynch.

CHECKOUT Owners analyze data, but use dealers for big repairs.

That means the technology is here to stay and construction mechanics are learning to deal with it. In some cases, the technological changes have prompted shops to outsource major repairs to dealerships, while still performing diagnostic work and preventive maintenance on their own. "You can’t stay current with technology, training and tooling," says Monnot, who manages a $190-million mobile fleet of 4,600 total machines, including 1,100 cars and trucks. "We can diagnose the problem, but can we fix it? Probably not. We have to call a dealer."

As a result, truck dealers are likely to profit from the new regulations and engines. At dealerships, labor charges vary in the U.S. between $75 and $80 per hour. But construction fleet managers say that newer EPA-certified diesel engines have a limited track record, so dealer-warranted work is one way to hedge bets.

"The labor is more expensive by going to the outside, but it is far outweighed by the warranty," Monnot says. "We’ve seen repetitive failures. The days of having a mechanic just go out there and start adjusting cables are long gone."

Construction truck owners are purchasing more extended warranties on new vehicles. Vanden Brook, whose $45-million municipal fleet contains 1,100 vehicles, including 225 diesel trucks, says he started buying extended warranties about four years ago in reaction to tighter diesel engine regulations. He calls the warranties "insurance."

Fuel economy on these engines still is a big question and owners are seeing mixed results. Lilly notes that his customers have been cautious to buy a large number of engines with new emissions controls. "Everybody has said on all the systems that fuel mileage is not as good as what it was before," he says. Most users are seeing, on average, a negative difference of 0.3 to 0.4 mpg, he adds.

Some disagree with those numbers and believe that their fuel economy actually has improved with EGR and ACERT engines. Monnot says his fleet has seen 7% to 10% gains in fuel economy since the new engines arrived. "I think it is going to get better than the 18% to 20% range," he says. Redding agrees that the newest roundof diesels are far more fuel efficient than previous ones. Vanden Brook also is seeing better fuel economy but says "it does not offset the cost of the engines." Engines are costing $3,000 to $5,000 more per unit, on average, owners say.

Suppliers of consumable engine parts are trying to appease skepticism by researching ways to economize on maintenance. "We have been in a constant state of development since 1993," says Jacoby. "Our biggest concern with engines is maintaining service intervals fleets are accustomed to."

Lubricant manufacturers have a huge challenge. In many cases, 400 hours has been common for an oil change on work trucks, but emissions controls necessitate shorter intervals, Jacoby says. As engines burn hotter and with higher volumes of sooty exhaust in the cylinders, the oil also has to counteract oxidation and viscosity buildup or engines will corrode and wear faster. Low-sulfur fuel and low-ash engine oil is helping the problem. Jacoby notes that new "CI-4" type diesel engine oil costs about $3.50 per gallon, up 2% to 3% more than its predecessor, CH-4.

Some call the rising prices for engines and maintenance a necessary evil for a cleaner environment. But construction owners also say the costs are difficult to justify to upper-management. Says Jacoby, "Today, people are willing to pay more for a quart of bottled water than a quart of oil."

(Photos by Paul Hartley for ENR)