Tires, engines, chassis and suspensions. World Wastes Truck Editor Bob Deierlein profiles several of the product improvements that have been announced in the past several months in these key components.
Talkin' Tires In the market for new tires? Tire manufacturers are unveiling an assortment of tire models with improved casing and retreadability warranties. For example, Goodyear Tire & Rubber, Akron, Ohio, has modified its Unisteel G300 Series tire line, extending the G300 Series casing warranty from four to five years.
The warranty sets the casing value at $100 through the original tread life and the tire's first retread life. It will retain this $100 value through an unlimited number of retreadings during the five-year warranty period, providing the processes are performed by Goodyear authorized retreaders using Good-year materials.
Size depending, most other Goodyear over-the-road truck tires have a casing value of $90 that includes the first 25 percent of the tire's retread life. Afterward, the casing value shrinks to $68.
Depending on service and proper retreading, Goodyear stresses that there are no disadvantages to retreading, and casings can be retreaded an average of 311/42 times.
The leading retreader, Bandag, Muscatine, Iowa, reports that it has improved durability by investing more than $74 million in its dealer system for new equipment.
A good share of that investment was spent on the latest inspection technology, like the 7110 NDI non-destructive casing analyzer which finds separations in the tire that could ultimately waste recovery fleets' money and increase downtime. It also detects penetrations, bad liner splices, poor repairs and other flaws.
Bandag has introduced six new application-specific products that are designed to maximize tire performance in a given vocational operation. Dealers study an operation and its equipment to recommend specific tires which would give the fleet the best return on their investment.
According to Michelin, Greenville, S.C., tires are the second-highest operating fleet cost behind fuel expenses. However, those costs are inter-related. All moving tires use fuel, but the less rolling resistance that tires have, the less fuel they cause the vehicle to consume.
Michelin proved this relationship in 1992 when it introduced its Ad-vanced Technology tires, which offer a 14 percent reduction in rolling resistance over the company's other tire lines. This reduced rolling resistance has led to nearly a 4 percent savings over competitive radials, according to the company.
Michelin's recent generation of fuel-efficient tires, the XZA2 and XDA2, provide the fuel efficiency of their predecessors while enhancing traction, handling, tread mileage and retreadability through the use of new tread compounds, and casing and tread designs.
To attain optimal fuel efficiency, the correct tire must be chosen for the specific application. For example, regional/local rough hauling vehicles that operate in hostile environments require rugged tires, equipped to with- stand scrubbing, pinches and punctures.
Michelin's all-wheel position XZE tire is designed for applications where turning and scrubbing influence tire life.
The XZA2 is optimized for steer axles, but is versatile enough for all-wheel position use.
The XDA2 drive axle is designed for long, even wear and improved fuel economy for 6 x 4 tractors.
It boasts a 26/32 tread depth for increased mileage, wide see-through grooves for wet-weather handling, and stabilized shoulder tread blocks to resist irregular wear, promote longer original tread life and reduced noise.
Retreads Gain Acceptance Don't fear the retread. After years of negative public perception, retreaded tires finally are enjoying the acceptance of fleet managers who purchased approximately 17.6 million retreaded medium- and heavy-truck tires.
Shedding the unfounded distinction of having a short life that ends in unraveling along the highway, re-treads now are used as replacements more than new tires.
Why have retreads lost their stigma? It appears that fleet managers finally are recognizing the savings. A quality retread can be purchased for about one-third of a new tire's cost - saving up to $1,000 per vehicle in annual replacement tire purchase costs. Plus, retreads deliver service and performance comparable to the more expensive new tires.
Considering that tire purchases comprise about 20 percent of a vehicle's maintenance cost, retreads deserve a second look.
Purchasing retreaded tires also can save valuable landfill space: Compare the 22 gallons of oil needed to manufacture a new truck tire to the seven gallons required to retread that same tire. Thus, with each decision to retread, 15 gallons of oil can be saved. In fact, last year alone, retreading accounted for saving 400 million gallons of oil. Since a quality tire can be retreaded an average of three times, retreading can reduce disposal problems by up to 75 percent.
What's Groovin' in the Cab Navistar International Corp., Chicago, reports the following new key features for its International 4000 Series:
* The first step into the cab is only 14 inches off the ground with non-slip, self-cleaning grating.
* A galvanized steel cab eliminates corrosion, and a protective urethane finish on paints enhances value.
* The 50-degree wheel cut lets drivers in and out of tight streets, pick-up points and dumps.
* Flat, clean frame rails allow easier body installation. Fuel tanks, batteries and oil reservoirs will not be in the way of body mounting.
The company applied its HEUI (hydraulically actuated, electronically controlled unit injector) technology to meet the proposed emission standards for the year 2004 which will reduce allowable truck NOx emissions to 2.4 grams emitted per brake horsepower hour - less than half the allowable level of today's heavy-duty truck NOx emissions.
Navistar also introduced its cold ambient protection (CAP), a software modification that is programmed into all new International diesel engines. CAP maintains combustion chamber temperature to ensure that fuel burns properly and more completely, preventing white smoke and eliminating residue and carbon deposits. This will increase engine life and improve cold-weather starts and idling.
Peterbilt Motors, Denton, Texas, introduces its medium-duty Model 330 in a 4 x 2 tractor configuration. The expansion of this product line increases Peterbilt's presence in the Class 7 market.
The Model 330 has a 50-degree wheel cut for maneuverability, and an all-aluminum, corrosion-resistant cab.
Also, Caterpillar 3126 and Cummins M11+E engines are now available in its Model 320 low cab forward. The new engines represent the first electronic engines available in this model.
The Caterpillar 3126 is a 7.2 liter, in-line six-cylinder, four-stroke, electronic engine available with ratings from 230 horsepower (hp) to 300 hp. The engine uses programmable electronic parameters to save fuel.
The Cummins M11+E is compatible with manual transmissions and the Allison HD series automatic transmissions.
Cummins Engine Co., Columbus, Ind., announces the Signature 600 engine, the first electronic dual overhead camshaft diesel which is rated at 600 hp, has six cylinders and 2,050 feet/lb. of torque, according to the company. It has a larger displacement than the Cummins 14-liter N14, but weighs about 300 lbs. less. Its overall dimensions are only slightly larger than the Cummins 11-liter M11.
The dual overhead cams have extra-wide lobes to reduce load factors and increase component life. One cam-shaft drives the high-pressure fuel injection system and the other drives the valves and a new engine brake system.
It has one-third fewer parts than the N14, partially due to the fact that the fuel and air systems are integrated into the electronic controls.
The dual cam design includes:
* Fuel injection pressures of 28,000 lbs. per square inch.
* Electronic sensors located throughout the engine and accessories that send performance data back to the electronic control monitor which then compares the numbers to "normal" performance specs. This enables easy detection of trends such as air compressor performance and fuel delivery systems to catch potential problems early. The system also will sense and protect the engine from failures, warning the driver before engine temperatures exceed normal limits.
* A variable output turbocharger with an electronically-controlled wastegate which performs differently at different speeds for higher performance and fuel efficiency. At low speeds, it performs like a small turbo, quickly pumping up the pressure for improved engine response. At high speeds, it functions like a big turbo, managing airflow to maximize performance and efficiency.
The Signature 600 engine, which will become available in the spring is designed to travel more than a million miles and requires oil changes at 50,000-mile intervals.
Suspensions and Transmissions Meritor Automotive Inc. (formerly Rockwell Automotive), Troy, Mich., manufactures the RHP Highway Parallelogram, a trailer air suspension system. This sliding tandem system is centered around a single, unified frame bracket rather than two separate trailing arm suspensions on a frame. Air springs are situated directly over the axles rather than behind.
This design also offers:
* Easy access to system components.
* Weight equalization to reduce frame stress and protect from tire, bearing and axle overload.
* A constant vehicle height regardless of load, equating to maximum interior volume and constant tire/road clearance.
* Increased stability. The increased roll stiffness controls trailer lean.
* User-friendliness. The air springs weigh only 20 pounds, attach with small bolts and can last more than a 1,000,000 miles.
* Versatility. It can fit almost any application, load, design height and environment.
* Fuel Mileage. Direct drive transmissions (the Direct 10 model) aid in fuel economy due to the direct route of torque travel.
Other fuel-saving options include a stamped steel spider available on the 16.5" x 7" Q Plus cam brake and the aluminum carrier option on the company's 40,000-lb. tandem axle (RT-40-145A).
The stamped steel spider offers a weight savings of 6.5 lbs. per brake when compared to 16.5" Q Plus brakes with cast spiders. A weight savings of up to 90 lbs. can be achieved with the RT-40-145A without sacrificing performance or durability, the company says.
The Engine Synchro Shift transmission system has eased manual transmission shifting by automatically synchronizing engine rpms to road speed during both up and down shifts. The system is available through several OEMs with a Detroit Diesel Series 50, 55 or 60 engine.
Finally, Meritor's Easy Steel front axles feature unitized hub assembly, inclusive of seals, bearings and a specifically-formulated grease, which reduces six wheel-end components into one unit.
Hendrickson Truck Suspension Systems, Woodridge, Ill., introduces the HN 462, the newest offering in the HN series of vocational truck suspensions.
Rated at 46,000 lbs., the HN 462 boasts a lightweight, beam and saddle. The installed weight is 933 lbs.
The VariRate Spring System's diagonally-mounted rubber springs act in compression and shear to deliver a smooth ride while in the empty or slightly loaded condition.
As the load increases, the rubber springs compress and stiffen for increased stability without affecting the ride.
To improve stability, spring centers have been increased by four inches. Combined with the VariRate Spring System, the wider spring centers eliminate the need for center bushings, cross tubes and lubrication common to suspensions and thus has no routine maintenance requirements.
Other notables from Hendrickson:
* The saddle is designed to save 77 lbs.
* The equalizing beam saves 90 lbs. over the former HN 460 beam design, and the elimination of the cross tube saves an additional 30 lbs. The HN 462 is standard with a 54-inch axle center.
* The new rebound control strap protects the bolster springs from excessive rebound tension.