Trucks: ConExpo’s big-bore bruisers

Two new on-highway trucks dominated this year’s ConExpo-Con/Agg show in Las Vegas in April. Both are powerhouse trucks, built to withstand the rigors of modern construction sites thanks to big-bore diesel engines, modern electronics, reinforced frames and enhanced cab ergonomics. But that’s where the differences end. Each truck, taken individually, is a testament to the heritage and culture of the company that produced it. Here are the highlights:

Mack’s Titan heavy-hauler
Mack isn’t pulling any punches with the launch of its Titan heavy transport, heavy construction tractor. Titan is powered by the all-new MP10, 16-liter diesel engine – making it the most powerful truck in Mack’s 108-year history, according to the company. “Make no mistake, this is Mack’s flagship truck,” says Steve Ginter, marketing manager, vocational products. “Mack research shows customers in these segments expect their truck to have several characteristics: It has to be reliable, durable and efficient. And it needs the horsepower to pull extremely heavy gross vehicle weights and gross cargo loads and visually demonstrate its power, durability and quality. Titan possesses all of those attributes.”

The truck is tall, with a commanding stance and high ground clearance. The cab is located behind a long hood and set high in a classic “heavy haul” position to insure excellent driver visibility. The higher cab position also improves airflow for underhood cooling requirements. Titan touts lots of chrome, including a large grill surround featuring four inches of chromed, cast aluminum and Mack’s new, twin cowl-mounted “Growler” air intakes, which Ginter says send “trashcan” style intakes back to the ’70s.

Massive torque to get loads moving
Lurking under Titan’s long hood is the new Mack MP10 – the most powerful engine every installed in a Mack vehicle. The MP10 is an inline, six-cylinder diesel, with single overhead cam and high-pressure fuel injection system. The engine will be offered with three horsepower ratings: 515, 565 and 605, all with the MaxiCruise torque rise. MP10 maximum torque ratings are particularly impressive: from 1,860 pound-foot to 2,060 pound-foot at 1,200 rpm – intended, Ginter says, to give Titan the “grunt” to pull heavy loads from a dead stop on a jobsite and get those loads quickly up to highway speeds. The MP10 is matched to Mack’s T300ES series 10-, 13- and 18-speed transmissions with triple countershaft performance. Eaton transmissions are available as optional equipment.

Titan rides on Mack’s Cornerstone chassis, which has been extensively tested and refined in Granite Class 8 models for several years now. The chassis is offered in three frame rail thicknesses – 8, 9.5 and 11 millimeters, with optional full or partial 5 millimeter inside channel reinforcements and application-specific crossmembers. A short, 41-inch front axle position increases load capacity while providing outstanding maneuverability. Mack engineers say the truck’s axle position, combined with its high ground clearance, gives drivers excellent approach angles when negotiating sharp inclines and uneven terrain.

On the business end of things, an air-assist clutch pedal is positioned low to help drivers engage it more productively with less leg effort. An additional foot pedal allows steering column adjustment while the entire cab rides on various highly engineered sound and vibration suppression systems to insure a smooth, quiet ride. These systems, including twin, wide-spaced air bags with shock absorbers to neutralize bumps and stabilizers to prevent cab sway help drivers stay comfortable, rested and productive even in harsh driving conditions.

Set-back maneuverability for International’s largest PayStar dump truck
International chose a working quarry outside Las Vegas to unveil its newest truck: the PayStar 5900i Set-Back Axle (SBA) model. The quarry setting was no accident. According to Phil Christman, vice president and general manager of International Truck’s Severe Service Vehicle Center, the 5900i SBA sends a clear signal to the trucking industry that International is, “committed to building heavy-duty diesel trucks that perform in the most severe conditions.” The new model, Christman adds, “Completes the PayStar line and shows there is now an International truck for all vocational requirements.”

The new Class 8 is available as either a tractor or a straight truck. Its set-back front axle is configured to meet the needs of contractors in severe service applications. The overall, set-back, wide-track design addresses the needs these customers have for front-axle load distribution and improved maneuverability.

You can spec the PayStar 5900i SBA with either a Caterpillar or Cummins diesel engine with up to 15-liters displacement and 625 horsepower. Peak torque registers at 2,050 pound-feet. The SBA rides on a 12.25-inch frame rail PayStar chassis, which International claims has the highest standard strength-to-weight ratio in the industry with a 2.3 million RBM rating. An optional double frame rail provides an increase to 4.7 million RBM.

Other standard 5900i SBA features include a cooling packaging designed for stationary applications up to 600 horsepower, 40-degree front wheel cut (with 425/65R22.5 flotation tires and wide-track axles), dual power steering gears that require less steering effort (for front axles 14,600 pounds and higher) and a heavy-duty front bumper with front tow pin capable of pulling up to 150,000 pounds.

In our February 2008 issue a typo mistakenly implies that Detroit Diesel’s amplified common rail fuel injection system reduces the DDIS engine’s fuel economy by 5 percent. In fact, the fuel system improves the engine’s fuel economy by 5 percent.