Cover Story/Productivity Guide: 2007 Heavy-Duty vocational trucks

Any preview of 2007 Class 8 vocational trucks will naturally focus on the extensive engine enhancements mandated by the 2007 Environmental Protection Agency’s Diesel Exhaust Standards. But reengineering trucks for substantially different engines, which include catalyzed traps, oxidation catalysts, NOx absorbers and selective catalytic reduction systems is an extensive task from an engineering point of view. And for many companies, it makes economic and design sense to undertake additional design changes while you’re preparing trucks to accept the new engines.

A plethora of power options

Freightliner has multiple resources to pull from when it comes to spec’ing vocational trucks. The company, along with stablemates Sterling and Western Star, is owned by Mercedes-Benz, which also owns Detroit Diesel. So in addition to Caterpillar and Cummins engines, Freightliner conventionals can be spec’d with standard Mercedes-Benz MBE 900 and MBE 4000 diesel engines or Detroit Diesel Series 60 power.

The heart of Freightliner’s conventional, vocational truck line begins with its M2 series and extends up to heavy-duty FLD SD models. The FLD SD is Freightliner’s largest vocational conventional truck. Accordingly, it is engineered for severe environments and extreme working conditions. It features a heavy-duty chassis with frame rails rated to 120,000 psi and a durable, yet lightweight, reinforced aluminum cab to help isolate vibration and noise and insure a more productive, rested driver.

You can optimize an FLD SD with either a set-forward front axle for maximum weight distribution or a set-back front axle for increased maneuverability. Steer axles are available with ratings up to 20,000 pounds, while drive axles can be spec’d up to 52,000 pounds, and optional pusher and tag axles are available as well. Freightliner’s TufTrac rear suspension is standard. It provides maximum traction in high articulation environments thanks to rubber-isolated pivot points and parabolic taper-leaf springs. These components work together to ensure a smooth ride, whether loaded or unloaded, minimizing wear and tear on the truck and the driver. The FLD SD can be spec’d with a variety of engine options up to 550 horsepower and 1,850 foot pounds of torque.

New electrical system further enhances body installation for M2 Series trucks
Medium-duty Freightliner offerings are centered on the company’s Business Class M2 Series, most notably the M2 112 model. It’s available as a truck or tractor with GVW ratings up to 66,000 pounds and optional 20,000-pound capacity front axles and suspensions. Good maneuverability is insured by front wheel cuts as great as 55 degrees, a set-back front axle and swept-back front bumper and fenders. In the rear, the Business Class M2 trucks are available with Freightliner’s TufTrac and AirLiner rear suspension options.

All Business Class M2 trucks support a wide range of bodies and chassis-mounted equipment. To aid in quicker and less expensive body installations, Freightliner has fitted all M2 trucks with a new multiplex wiring system standard, clear frame rails back of cab and a variety of horizontal and cab-mounted exhausts. Standard power for the M2 series is the Mercedes-Benz MBE4000 series engines.

Business Class M2 interior comforts include a 2,500-square-inch windshield and low profile dash for optimized driver visibility. Standard cab features include ergonomic, comfortable interiors, wide door openings, low step-in heights and interior and exterior grab handles.

Return of the Paystar

For the past 20-odd years, International’s Premier Class vocational truck has been its 5000 Series. Earlier this year, International announced it would revive the 5000 Series’ original name, the Paystar, for all trucks included in this model family.

Along with the old-new name, International introduced a lightweight mixer package, thanks mainly to a new engine offering: the 330-horsepower Cummins ISL diesel engine. Combined with the truck’s overall lightweight design and 12-inch frame, legal concrete carrying capacity has been increased to 10 yards – an increase of 71/2 percent over previous models. For the Paystar 5600 – the largest Paystar mixer available from International – legal payload capacity increased to 11 yards – an increase of 6.8 percent.

Paystar trucks are more than concrete mixers, of course. Regardless of application, you can spec a Paystar with a variety of options, including a severe-service 12.5- inch frame rail system and wheelbases up to 300 inches. Set-back axles are available for certain models, and all models feature clean frame rails for easy body installation. Factory frame piercing is available as an option to further ease body installation demands.

A full line of engine options are available for Paystar series trucks, including International’s MaxxForce diesel engines; Cat ACERT C-11, C-12, C-13 and C-15 units; and Cummins ISM and ISX diesels.

New hood, interior highlight 7000 Series updates
For many OEMs, new 2007 engines mean new front-end arrangements, and International’s 7000 Series vocational trucks are no exception. But International didn’t simply slap a new hood onto these trucks. Realizing that ground clearance and front PTO capabilities are an important consideration in many construction applications, International engineers made sure the truck’s new radiator design did not extend down into and below the truck’s frame rails despite its larger size.

The 7000 Series’ new hood is a three-piece design, which will help hold replacement costs down in the event of an accident since the components can be replaced piecemeal. The new hood features other design enhancements as well, including dual air intakes, rounded headlamps, a hood hatch for snowplow applications and stronger front fender extensions. In addition, the new front-end allows 7000 Series trucks to accommodate engines from International, Cat and Cummins.

International’s 4000 Series trucks are the core of its medium-duty offerings, beginning with the Class 5 4100 model and extending to Class 6 and 7 4200 models. This truck series underwent an extensive redesign several years ago – the first such overhaul in a quarter of a century – with the goal of developing a modern truck incorporated with world-class technology optimized for vocational hauling and delivery applications. As a result, 4000 Series trucks offer advanced electronics systems, simplified maintenance combined with a comfortable ride and ergonomic cab. International’s VT 365 diesel engine is the standard power plant in 4100 models and is mated with a standard Allison automatic transmission to help less-experienced drivers be productive behind the wheel.

Cat C-9 and Paccar medium-duty diesels among new engine offerings for ’08.

Kenworth looks ahead to the coming year with a host of new options for its vocational customers. The company’s W900S vocational truck will be offered in an all-new extended day cab version. Several engine options will be new as well, including the additional of Caterpillar C9 C-9 engines and new, Paccar proprietary medium-duty diesel engines. All Kenworth trucks produced with 2007 EPA-compliant engines will be designated 2008 models.

In addition, Kenworth has added new, high-performance cooling systems to its Class 8 offerings. Developed in close coordination with Caterpillar and Cummins, the new cooling systems offer advanced airflow solutions while controlling weight and cost to insure optimum performance with 2007 low-emission diesel engines. Medium-duty Kenworth trucks will come standard with Paccar’s PX-6 or PX-8 proprietary diesel engines.

The Kenworth T800 is the company’s workhorse vocational truck. It can be configured for applications as diverse as line haul tractors with Studio AeroCab sleepers to severe service off-highway dump trucks. A set-back front axle provides high maneuverability on crowded jobsites and a wide array of weight-saving options can be spec’d if payload maximization is a priority.

The T800 can be spec’d in 116 and 123 BBC configurations. Front axle ratings range from 12,000 to 24,000 pounds. Rear axles offerings start at 21,000-pound singles and range up to 70,000-pound capacities for tandems and tridems. All T800 models feature 59-inch taperleaf springs for a smooth ride and the truck’s wheelbase is adjustable in 1-inch increments. Four different frame rail sizes allow you further options to match vehicle strength and weight requirements to your specific construction applications. Three radiator sizes allow you to match cooling performance to your needs: You can spec radiators with 1,180, 1,440, and 1,780 square inches of surface area. Engine sizes from 9- to 15-liters, and include 600-horsepower options available for models.

Comfort and safety are cab hallmarks on the T800. A sloped hood provides drivers with good visibility to all operating quarters, but an optional straight hood can be spec’d to give the truck a more traditional styling appearance. Both versions are aerodynamically engineered to boost the vehicle’s overall fuel economy.

Low operating costs and high productivity highlight T300 design
Kenworth’s medium-duty T300 is designed to provide the maneuverability, visibility and versatility required in a wide range of vocational applications. To this end, T300 models feature DayLite doors and peeper windows, a 20-degree sloped hood, 50-degree wheel cuts, one-piece windshield and optional cab corner windows. The aluminum and fiberglass cab features Huck-bolted construction for durability and longevity. Cowl-mounted mirrors add strength and durability for longer life and lower operating costs.

Serviceability demands are met by the inclusion of a 90-degree tilting hood for easy access to the engine compartment. Air brakes are standard on the T300, but you can spec optional hydraulic brakes. Front axle ratings for the T300 range from 8,000 to 14,600 pounds. Rear axle can be spec’d with capacities from 16,000 to 40,000 pounds. Paccar’s new PX Series engines are standard in T300 models. Transmission offerings include Allison automatic and Eaton Fuller manual units.

New engines, new interiors

Mack’s vocational truck offerings for 2007 revolve around its recently introduced Granite MP Engine Series, available in both axle forward and axle back versions. All Macks available next year will be 2008 model year products. In addition to the Granite, these 2008 models include Mack Pinnacle models focused on highway tractor business, and the company’s MR and LE cab over vehicles for refuse and specialty service delivery.

All Mack Granite models are built on the company’s Cornerstone chassis with new parent frame rail extensions and triple element choices available for 2007. The chassis features flared rails to accommodate a new, larger cooling system. This cooling package is performance tuned for the low-emission engines and has a 1,380-square-inch-radiator with new engine-mounted shrouds and fan rings. The standard fan is a 32-inch Borg Warner with a choice of three fan clutches: an on or off version; an electronically modulated E-Viscous unit; or a heavy-duty multi-speed fan that can be locked on in high-temperature applications. Other new cooling package features include a new radiator-mounted expansion tank, coolant piping, charge-air-cooler piping, air intake piping, power steering coolers and cross-flow charge-air-cooler. To improve air circulation throughout the engine compartment, Mack engineers opted to mount the MP series lower and farther rearward in the Cornerstone chassis.

The cabs of both the Pinnacle and Granite MP Engine series are deeper and quieter. Customer input and ergonomic research are reflected in the adjustable steering column, seat, pedals and controls that together create an optimal driving position. All Macks now come standard with the next generation of the company’s Vehicle Management and Control System, which provides a wide variety of customer-programmable features to boost productivity, efficiency and profitability.

High-pressure fuel injection at the heart of Mack’s new engine family
In 2007, MP Series engines will be offered in two versions, each with Econodyne, Maxidyne and MaxiCruise torque curves for specific trucking applications. The MP7 is an 11-liter diesel engine available in six ratings from 325 to 405 horsepower. Torque ratings for this engine range from 1,260 to 1,560 foot pounds. The MP8 is a 13-liter engine with horsepower ratings from 415 to 485horsepower, matched to torque levels ranging from 1,540 to 1,700 foot pounds.

Both the MP7 and MP8 feature an Ultra High Fuel Injection Pressure system delivering fuel injection pressures at 35,000 psi for improved combustion and lower emissions. The system is combined with an enhanced dual-solenoid fuel injector for optimal actuation and rate shaping capability.

A high-performance cooled EGR system precisely controls the flow rate of exhaust gases through the engine. A sliding nozzle variable geometry turbocharger with electronic actuation instantly provides necessary EGR back pressure, while a hydraulic EGR valve insures proper EGR flow through the system. A Delta-pressure flow sensor provides precise measurement of the EGR flow rate and integrate the signals back to the turbo actuator and EGR valve through the closed-loop V-MAC IV electronic management system.

Other MP Engine Series highlights include a single overhead camshaft and single-piece cylinder head design to reduce engine vibration and increase component life. A low-return-flow fuel system cools fuel in the engine, not the fuel tank, providing consistent fuel temperature to the injectors regardless of extreme summer heat or frigid winter cold.

A venerable workhorse bids adieu

The Model 379 is arguably the most recognized vocational truck in Peterbilt’s lineup. But after a 20-year production run, the 379 is being put out to pasture. In recognition of the truck’s legacy, Peterbilt has authorized the last 1,000 production models of the 379 to be designated special Legacy Class Edition trucks.

Replacing the Model 379 is Peterbilt’s new Model 389 conventional truck, with incorporates key styling elements of its predecessor while taking advantage of advanced vehicle technologies and improved aerodynamics.

Externally, the 389 features more rounded features than its predecessor, which contribute to the aerodynamic efficiency of the design. The most notable appearance changes are the lightweight aluminum hood, a punched-oval pattern grill and one-piece aluminum surround, polished-aluminum fender reinforcements and all-new headlights. The aluminum hood is designed to be durable and feature improved fit-and-finish. It opens to a full 90-degrees for engine maintenance and a proprietary anti-blown-down locking mechanism prevents unintentional closing.

While the Model 389 can be spec’d for vocational applications, Peterbilt’s new Model 367 and Model 365 now form the backbone of the company’s work truck offerings. Both will be available in set-forward and set-back front axle positions to comply with various state and federal bridge law requirements. In addition, the Model 367 is available in a special heavy haul configuration that features a high-capacity cooling system to accommodate the highest horsepower engines available.

Both models feature a new chassis design for set-forward and set-back front axle configurations. In each case, axle placement is optimized for optimal maneuverability and weight distribution as well as an enhanced ride for operator comfort and productivity.

The hoods of the new Model 367 and Model 365 are made from a durable composite material. A new, one-piece aluminum crown and stainless steel grille provide impact-resistant performance while adding distinctive styling. These hoods also have a proprietary anti-blow-down locking mechanism that keeps it in an open position to prevent unintentional closing, and open a full 90 degrees to facilitate engine access during servicing. Both trucks have a new bumper that can accommodate both a center hook configuration and a dual, removable pin configuration that meet TMC towing requirements.

New engine options
Peterbilt will offer a new power option for its medium-duty Model 330, Model 335 and Model 340 trucks next year: The Paccar PX-6 and PX-8 diesel engines. “These new engines were developed from a proven platform,” notes Dan Sobic, general manager and Paccar vice president. “They meet the full range of horsepower and torque needs for medium-duty markets, and provide exceptional reliability and serviceability.”

The PX-6 will be offered in 200 to 325 horsepower versions with torque ratings ranging from 520 to 750 foot pounds. It will be the standard engine for Class 6 Model 330 and an option in 2007 Class 7 Model 335 trucks.

For higher power applications, the PX-8 features ratings from 240 to 330 horsepower and torque ranging from 660 to 1,000 foot pounds. It will be the standard engine for the Model 335 and Model 340. Both engines have an in-line, six-cylinder design with four valves per cylinder, a high pressure common rail fuel systems and variable geometry turbocharger.

Power offerings from 190 to 450 horsepower

Talk heavy-duty vocational trucks with a Sterling dealer and you’ll find three basic models to choose from: the A-Line, L-Line and Acterra. All receive upgrades for 2007, including new, low-emission Mercedes-Benz MBE 900 and MBE 4000 and Detroit Diesel Series 60 diesel engines. In the cab, all Sterling models will switch to suspended brake pedals and a revised accelerator pedal design as well as spiced up door trim options.

Sterling’s big dog conventional
L-Line Sterling trucks are designed to maximize payload, uptime, durability, and driver comfort in heavy-duty dump, mixer, crane and specialized hauling applications. You can spec an L-Line with four different BBC choices, including 101-, 111-, 113- and 122-inch wheelbase versions and GVW ratings up to 94,800 pounds, making this Sterling’s go-to heavy-duty truck. If bridge formula laws are a concern, Sterling offers a wide range of lightweight options to insure compliance, including an aluminum cab, Centerfuse brake drums and Sterling’s proprietary TuffTrac tandem rear suspension system.

Regardless of configuration, all L-Line models feature modern styling, easy service access to help maintain your uptime, tough frames and increased engine-cooling capacity. A host of engine options can be spec’d for L-Line models, all of which meet impending 2007 EPA emission regulations. MBE 900 and 4000 engines are standard, but you can request Detroit Diesel Series 60 power plant, or one of Cat’s C-13 and C-15 units. Multiple power ratings from 190 up to 450 horsepower are available.

Extended cab Acterra to debut next year
Don’t need a big dog on your job? No problem. You can always go with Sterling’s medium-duty Acterra conventional truck, which can be configured in models from Class 5 up to Class 8. The Acterra’s design is based on Sterling’s heavy-duty heritage, including many design cues taken from L-Line models. This is reflected in Acterra’s optional 120,000 psi frame, 46,000-pound tandem axles and engines rated up to 330 horsepower. Interior comfort was given high priority during Acterra’s design process, resulting in a roomy, comfortable cab with good forward, lateral and downward sightlines.

New in 2007, you’ll be able to spec a 136-inch extended- cab Acterra model with the choice of bench or folding rear seats, bunks or cargo access doors available for the back cab area. In the fall of ’07, you’ll be able to request optional power windows and locks for both front and rear doors.

Acterra engine options are based on three different engines, including the standard Mercedes-Benz MBE 900 diesel engine. You can also opt for a Caterpillar C-7 unit, or a Cummins ISC engine.

I-Shift transmission highlights Volvo upgrades

Volvo’s entire truck diesel engine family, including D11, D13 and D16 units, is ready for 2007 EPA certification. These are the standard engines for the Volvo VHD heavy-duty vocational truck, which is available in daycab configurations as a conventional or tractor. According to company officials at a press conference in late September, the new engines deliver up to 3 percent better fuel economy than comparative 2006 engine models (when both sets of engines are tested using low sulfur diesel fuel. In order to show its support for the new engines, Volvo is making its GPS-based Volvo Link Security and Volvo Action Service systems standard for three years on all trucks equipped with the new engines. These systems will help insure prompt technical support anywhere in the country at any time of day. Both systems will provide early warning of potential trouble and give owners and drivers 24/7 access to Volvo’s customer support system and technical expertise.

Volvo also unveiled its new automated manual transmission, available on its complete line of trucks. Dubbed I-Shift, the new transmissions were designed by the same team that developed the electronic control systems for the D-Series engines to ensure a completely integrated driveline package.

There are three I-Shift models offered in five different feature packages tailored to meet individual application demands. The transmissions have been heavily road-tested since their debut in Europe in 2002. In fact, the current I-Shift series is the third generation of Volvo’s family of automated manual transmissions. Thanks to its advanced electronic control system, I-Shift transmissions continuously monitors the grade, vehicle speed, acceleration, torque demand, weight, rolling and air resistance. Using this data, I-Shift continuously predicts and selects the most efficient utilization of the engine. An easy-to-use driver interface monitor provides critical gear information, including gears available for up- or down-shifting should the driver opt for manual control of the transmission.

Safety and productivity rule VHD design
Volvo’s VHD vocational truck features front axle spring suspensions available from 12,000- to 22,800-pounds capacity. A wide range of Eaton and Meritor rear axles feature capacities from 21,000 to 65,000 pounds (tandem).

Economy and safety are two of Volvo’s core principles, a policy reflected in the VHD’s cab, which is crafted from high-strength steel. To maximize structural integrity, Volvo welds, rather than rivets, the cab. Standard break-away mirrors lessen the chance of expensive body panel damage, while an optional three-piece bumper allow easy end cap replacement should it be required. The VHD hood features a standard three-piece design for easy repair or replacement, while rubber isolator mounts allow it to flex independently of the cab, reducing component stress and damage.

Inside the cab, a panoramic, 2,000-square-inch windshield and sloped side windows provide good drive visibility both on the road and on jobsites. Volvo engineers designed the VHD to deliver a smooth ride in all traffic conditions, whether loaded or not. Just as important, the Volvo T-Ride suspension rides on trunion-mounted springs and rubber towers for excellent traction and up to 17 degrees of articulation in off-road conditions.

All VHD models are designed with weight optimization as a priority and are PTO ready. You can spec optional aluminum intermediate crossmembers to save even more vehicle weight. Additionally, the back of the VHD’s cab area is kept as clean as possible to insure closer body fits and better weight transfer to the truck’s front axle.

Western Star
Western Star’s offering of “premium vocational” trucks is largely centered on the company’s 4900 model, although contractors engaged in extreme applications can select its 6900XD model with 175 tons of gross cargo capacity and Cat engine options rated up to 625 horsepower.

A new front wall design is Western Star’s most notable 2007 upgrade. This new firewall design incorporates updated diagnostic capabilities while allowing better electrical routing and accessibility and streamlined air routes into the cab.

A new “dead pedal” has been added to the floorboards of all Western Star models to provide an ergonomic foot rest for improved driver comfort and better air line connection protection. As a bonus, the new pedal layout allows key electrical connections to be serviced from the ground without having to remove front wall-mounted equipment.

Western Star has also upgraded the electrical systems in its trucks by moving to a modular design concept. This new design improves serviceability by making it easier to isolate individual electrical circuits and diagnose problems in the field. This upgraded system includes SAE J1587/J1708 and J1939 standards with diagnostic access via a nine-pin connector located under the truck’s dashboard.

Engine choices to 515 horsepower
There are essentially five 4900 versions available from Western Star in 2007. The 4900FA trucks are set-forward front axle models, configured for optimal weight distribution in heavy-dump applications. If maneuverability is a priority, you can spec the 4900SA, which features a set-back front axle for better wheel cuts and a tighter turning radius. Both versions are available in a standard 123-inch BBC version or optional 109-inch BBC configuration and can be spec’d in twin-steer versions and all wheel drive as well. Western Star’s flagship set forward extended hood highway model, the 4900EX, features a 132-inch BBC length and two engine choices rated up to 515 horsepower. All 4900 versions come standard with Detroit Diesel Series 60 engines and offer Caterpillar C-13 and C-15 diesel engines as optional equipment. The lightweight and powerful MBE 4000 diesel engine is also offered for the 4900 series.