Emissions Systems Head Up New Truck Technology
Here’s the latest from engine and on-/off-road truck manufacturers
It’s a wide-sweeping change, and the effects are still being felt throughout the industry. October 1, 2002, was the deadline for on-highway truck engine manufacturers to comply with new federal regulations for exhaust emissions. On that date, the United States Environmental Protection Agency (EPA) required diesel engine manufacturers to restrict nitrogen oxides (NOx) to 2.5 grams per brake-horsepower-hour and to cut particulate emissions to 0.1 gram per brake-horsepower-hour. It’s a tough rule.
Cummins was the first manufacturer to launch a diesel truck engine that complied with the new rule, and most other engine manufacturers also have followed suit. Cummins markets two engines—the 15-lit. ISX and the 10.8-lit. ISM—that use a technology called cooled exhaust gas recirculation (C-EGR) to meet the regulations. Horsepower ratings on the ISX range from 385 to 565; the ISM ranges from 280 to 370 hp. And through a program of “Banking and Trading” exhaust emissions, Cummins can market its 8.9-lit. ISL and 8.3-lit. ISC engines as EPA-compliant. Another smaller Cummins engine has emissions well below the EPA standard, and Cummins can trade those reductions for a higher level of emissions in the ISL and ISC engines. Horsepower ratings on the ISL range from 310 to 335; the ISC ranges from 240 to 330 hp.
“We run the engine through a test cycle, and we have to demonstrate that we can meet the standard,” states Roe East, director of product management at Cummins. “I think cooled EGR is very effective at reducing NOx. With EGR, we take exhaust gas out of the exhaust stream, cool it, and put it into the intake side of the engine. As that gas mixes with the air and fuel, it inhibits the combustion process somewhat. You get a lower flame temperature and lower NOx levels. It is a very proven technology and has been used for years on engines. There are more than 12,000 Cummins engines with cooled EGR in real-world service today, and they have accumulated over 270 million miles of experience.”
Progress at Caterpillar
Caterpillar’s diesel engine builders have chosen a different path. Rather than use C-EGR technology or some variation of it, Caterpillar has developed ACERT, which stands for advanced combustion emissions reduction technology. Caterpillar did not meet EPA’s October 2002 deadline with ACERT, and as a result, the company is paying fines for noncompliant engines.
In the meantime, Caterpillar is selling so-called “bridge engines” that bridge the gap between older engines and those with ACERT systems. The bridge engines, which use oxidation catalyst technology, became available in October 2002. They are the 3126E, at 190–330 hp; the C10, at 305–335 hp; the C12, at 335–430 hp; and the C15, at 435–525 hp.
With ACERT, the C10 and C12 have become the C11 and C13 engines. The C13 and C15 engines became available this October with ACERT, and the C11 will be available in December 2003. In addition, a C9 engine, with 275–400 hp, may be well suited for some construction applications. According to Caterpillar, by January 2005, all of its engines sold for construction trucks will have ACERT systems.
Recently, Caterpillar announced the availability of its C18 engine with ACERT technology. The C18 is an 18.1-lit. off-road engine with five ratings from 575 hp to 765 hp. Cylinder heads on the C18 feature cross-flow design and four valves per cylinder. The company claims that this design provides better distribution of air throughout the combustion chamber. In turn, that makes combustion more complete and emissions are reduced. The C18 also uses the Cat electronic fuel injection system, which has millions of hours of proven experience.
Highlights of the Latest On-/Off-Road Truck Technology
Mack recently introduced its Granite series of construction trucks, which will replace the popular RD series. Mack has built the RD series for 38 years and has announced that the last RD truck will be made December 1, 2003.
The Granite has a galvanized steel cab but is designed to be an exceptionally lightweight vocational truck without sacrificing durability. A number of Granite components are aluminum, including the front bumper, the grille surround, the grille, and the fuel tanks.
The Granite is offered in two models—the CV7 or the Granite Bridge Formula. Designed primarily for southern California or Arizona, the bridge formula has a trailing tag axle, an aluminum front motor support, and a lightweight 20,000-lb. steering axle. You can get a Cummins 8.9-lit. engine in the Bridge Formula—making it 400 lb. lighter than with a Mack engine. “The Granite series allows customers to spec weight-savings components to match their applications,” points out Steve Ginter, Mack’s vocational product manager.
“The Granite has a larger cab and much greater visibility—you can see 14 feet in front of the bumper,” he continues. “It’s got a new door design with larger window openings—you can see the front left fender through the left window.”
Both Mack’s AMI series of high-torque-rise engines and the AI series of Econodyne engines are available in the Granite. The AMI engines have a 60% torque rise and are available in 300-, 335-, and 370-hp models. The AI series ranges from 300 to 460 hp.
Ginter states that Mack meets EPA emission standards with internal EGR systems. The introduction of exhaust gases into the combustion chamber requires a delicate balance. Bringing back more exhaust gases will reduce combustion temperatures and NOx levels, but too much exhaust gas will increase particulate emissions.
“We were able to get the same horsepower and the same oil-change intervals and have only a minimal impact on fuel economy with EGR systems,” Ginter relates. He estimates that EGR increases fuel usage by 0–5% on average.
At International Truck and Engine Corporation, all construction trucks and trash haulers are called “severe service.” That includes the 7000 series and 5000 series trucks. All 7300, 7400, and 7500 trucks have International engines. In the 7600 series, International offers Cat C10 or C12 engines with up to 430 peak hp or the Cummins ISM engine with up to 385 peak hp.
“We will meet emission requirements through cooled EGR systems by January 2004,” maintains Bill Sixsmith, severe service marketing director at International. “When the October 1  deadline came out, we were assessed a small fine, and the government said we didn’t have to meet the more stringent regulations until January ‘04.” He says the company’s EGR systems require a larger-capacity radiator and a new turbocharging system.
A major differentiator for International’s 7000 series is its Diamond Logic electrical system. Instead of cutting into chassis electrical systems to wire the body’s electrical functions, International uses a remote power module that body companies simply plug into. The system has an electronic controller, uses just nine pairs of twisted wires to handle all electrical functions, and can self-diagnose electrical problems by indicating specific fault codes. Many truck problems are electrical, and Sixsmith says this new system can greatly reduce diagnostic time.
Freightliner offers an extensive lineup of construction trucks. At the heavy end is the FL 120SD (severe duty) with either a set-back front axle or a set-forward front axle. The set-forward model has a 120-in. BBC (bumper to back-of-cab) and can carry up to 1,500 lb. more than the set-back model. Engine options on the set-forward model include Detroit Diesel, Cat, and Cummins units up to 600 hp.
Both Freightliner and Sterling trucks feature the TufTrac suspension, a severe-duty, six-rod vocational system with the advantages of high articulation, good weight equalization, and a good ride. TufTrac combines taper-leaf springs and a rubber elastomer center pivot to achieve good articulation and requires no lubrication or regular maintenance. (Sterling trucks have their origin as Ford’s heavy-duty line, which Freightliner bought. See more below.)
Freightliner’s Business Class mediums begin with the FL 50 and FL 60 but can handle larger jobs with the FL 70 medium and the FL 80. The FL 70 comes with horsepower ratings up to 300 and gross combination weights up to 50,000 lb. On the FL 80, gross vehicle weight ratings range up to 64,000 lb.; again, its horsepower ranges up to 300.
The FLD 112SD has a set-back front axle and a short, 112-in. BBC. The 112SD can fit engines up to 400 hp and is available from Cat, Cummins, or Detroit Diesel. All-wheel drive is offered as well.
Peterbilt’s main construction vehicle is the Model 357, which is available as a truck or a tractor but mainly is sold as a truck. If you want a construction tractor from Peterbilt, you probably want a Model 379 or 378, which specs out lighter and can achieve higher payload weights.
“The 357 has a new set-back hood and front axle,” describes Ray Paradis, director of vocational markets for Peterbilt Motors. “The deeper slope to the hood provides better visibility.” The 357 comes in three hood lengths and two front-axle positions. Cat and Cummins engines are available up to 475 hp.
The 357 has an all-aluminum cab, and Peterbilt claims it is the lightest-weight truck in the industry. “You can spec the truck with a number of aluminum features to give you a lightweight truck or tractor, which equates to higher payloads,” notes Paradis. He maintains that the construction business is very important to Peterbilt and has helped support sales in the last year.
Sterling Truck Corporation recently announced the availability of the Dana Spicer Central Tire Inflation (CTI) System for L-line vehicles. Truck operators can easily change tire pressures while in motion, allowing trucks to meet the demands of off-road use and soft terrain. CTI operates by using the vehicle’s onboard air compressor. Steer-and-drive tire pressures are microprocessor-controlled to maximize their tractive effort. Operators can choose from three pressure modes: highway, for high-speed travel on paved surfaces; off-highway, for easy operation on unpaved surfaces; and emergency, which is extra-low pressure to help free a stuck vehicle or to handle other extreme conditions.
Sterling’s L-line offers four BBCs: 101, 111, 113, and 122 in. Engines, up to 600 hp, come from Cat, Cummins, Detroit Diesel, and Mercedes Benz. Both manual and automatic transmissions are available. Front axles reach 22,000 lb., and rear axles go up to 52,000-lb. capacity.
For its Acterra medium-duty and vocational truck, Sterling recently introduced a factory-authorized all-wheel-drive conversion. The feature is manufactured by Fabco Automotive Corporation and now will fit all Acterra 4x2 versions; conversions for Acterra 6x4 trucks are expected later this year. The conversion is offered with front-axle ratings of 12,000, 14,000, or 16,000 lb. and comes with a choice of one- or two-speed transfer cases.
Volvo’s primary construction truck is the VHD, which can be spec’d as a truck or a tractor. The tractor comes standard with a 113.6-in. BBC and a Volvo D12 engine boasting 365 hp.
To meet EPA’s October 2002 emissions standard, Volvo uses an EGR system with V-Pulse technology. The system does not require a variable geometry turbocharger to achieve the EGR necessary to reduce combustion emissions. Volvo reports that V-Pulse technology achieves EGR “by harnessing naturally occurring engine pressure as a means to reintroduce up to 30% of the combustion by-product back into the intake mixing chamber.”
According to the company, Volvo’s 2003 VHD 200 model features an automotive-inspired interior for maximum driver comfort and safety. To minimize stress and fatigue, the interior features a wrap-around dash, and gauges and switches are within easy view or reach. A primary display computer limits what systems the driver can operate while the vehicle is in motion, thus ensuring that attention is directed to driving. Other key features of the VHD 200 are a single-rail frame, which is lighter than a double frame. In addition, the truck has clear space in back of the cab and on top of the frame to simplify body installation.
Kenworth’s mainstream construction truck is the T800, which has a set-back front axle and is offered with two BBCs: 112 and 121 in. “The set-back axle makes it easy to load up the front axle and gives it a good turn angle,” remarks Mark Hampson, a senior applications engineer at Kenworth Truck Company. As with Peterbilt, Kenworth is a division of PACCAR Inc. The T800 can accommodate any one of three Cat engines up to 525 hp or either of two Cummins engines to 565 hp.
Front axles from 12,000- to 22,000-lb. ratings are available on the T800, and rear axles are offered from 21,000-lb. single to 70,000-lb. tridems. Kenworth markets seven frame-rail sizes to match strength and weight requirements. A sloped hood for better visibility is standard, but you can spec an optional straight hood for a traditional look.
Another Kenworth vocational truck is the W900, which can accommodate up to a 600-hp engine. The truck has a long hood and cathedral grille and comes with either a 121-in. or 130-in. BBC. Rear axles range up to 52,000-lb. tandems.
Western Star, which is owned by Freightliner, features an extensive lineup of construction trucks, including the following:
- The 4900 EX, which has a 132-in. BBC and up to 58,000-lb. rear-axle capacity
- The 4900 SA, with two BBCs—109 and 123 in.—and up to 58,000-lb. rear-axle capacity
- The 4900 FA, with two BBCs—109 and 123 in.—and up to 52,000-lb. rear-axle capacity
- The 4900 EX dump truck, with a 132-in. BBC and engines from two manufacturers
- The 4900 FA dump truck, which can be spec’d with rear axles up to 58,000 lb.
All trucks can be spec’d with any of a full range of manual, automated, and automatic transmissions. And all of the above trucks can take engines up to 600 hp. Western Star is a popular nameplate among dump truckers and freight haulers in the Midwest and Northeast US.
Author's Bio: Daniel C. Brown writes on safety and technology in the construction industry.