For bulk haulers, the premise is simple: Weight savings transfers to payload and every pound that can be spec’ed out of a vehicle’s overall weight without sacrificing durability, reliability or safety is an extra pound of revenue generating freight.
To calculate the value of lightweight components, fleet managers in these operations rely on cost-benefit analyses to determine whether an additional investment in lightweight specifications is worthwhile and if lightweight components can be cost justified. In some cases paying extra to save weight is proven to be cost effective while in others the added cost outweighs the value of saving a few pounds.
For general freight haulers, saving weight to increase payload may not be as simple an equation because in these operations lightweight doesn’t necessarily mean higher payloads. Another factor to consider, however, is that reduced weight in over-the-road operations may mean improved fuel economy. General freight motor carriers may therefore want to explore the lessons bulk haulers have learned over the years about spec’ing light, not for the ability to carry more cargo but to save fuel.
To help fleets address the need for lighter weight specifications, truck, system and component design engineers always are looking for ways to take weight out of their products. As a result, the industry’s leading manufacturers now offer a wide range of systems and a variety of component options all designed to reduce weight.
One of the most popular lightweight options for Class 8 tractors and trailers are aluminum wheels. Kings County Truck Lines, one of the largest milk and dairy haulers on the West Coast, has been using Alcoa aluminum wheels for more than 20 years.
“The Alcoa wheels save us 558 lbs. per unit,” says Don Chabiel, vice president of facilities and equipment. “That lets us haul 65 gallons of additional legal payload per trip. Multiply that by the thousands of trips our trucks make each year, and we end up with a lot of extra revenue.”
Accuride also offers aluminum wheels for trucks. Forged from a single piece of aluminum, according to the supplier, the aluminum wheels are engineered to be lightweight, which allows for increased revenue from greater payloads and fuel savings.
Weight savings also are available by utilizing single wide based tires, which take the place of and weigh significantly less than a set of dual tires and wheels. While weight savings depend to some extent on what kinds of tires and wheels a fleet is using, manufacturers agree that savings are possible.
For example, converting to its Greatec radials could save significant weight, according to Bridgestone/ Firestone. If a customer already is using aluminum wheels for its dual fitments, the company says converting to Greatec radials could save more than 600 lbs.
For a fleet that has not yet converted to aluminum wheels, changing to Greatec radials with aluminum wheels might save close to 1,200 lbs., according to the company.
Similarly, Michelin says that its X One line of single wide based tires offers significant weight savings.
In fact, the company says that the tires are designed to provide a combined weight savings in the range of 750 lbs. to 1,350 lbs. per tractor-trailer combination.
Axles and suspensions
Many axle and suspension products also are designed with weight savings in mind. For example, the Hendrickson Composilite FX is a 13,500-lb. capacity lift axle for trucks and trailers weighing less than 850 lbs., tipping the scales at more than 300 lbs. less than previous Hendrickson models, according to the company. Composilite features aluminum beams that provide the lightweight material for an optimized design that also reduces packaging space, the company says.
Hendrickson’s HAS Series of lightweight air suspension systems also is available. The HAS 40LH, the manufacturer notes, is one of the lightest 40,000-lb. capacity air suspensions available, helping maximize payloads in line-haul applications. Also offered by the company is the Haulmaax Series suspension for vocational applications where lightweight is essential. The lightweight design of the system makes it hundreds of pounds lighter than steel spring suspensions, Hendrickson says.
Dana Corp.’s Commercial Vehicle Systems group recently announced the start of production of its new Dana Spicer RS 40 SmartRide trailer suspension. The manufacturer’s newest air ride trailer suspensions were designed with shape optimization and analysis software, which resulted in roughly 60 lbs. of weight savings for increased payloads and improved fuel efficiency, the company says.
The Dana Commercial Vehicle Systems group also has introduced the Dana Spicer SmartRide RN40 trailer suspension series. The system is billed as its lightest slider assembly to date with weight reductions of more than 200 lbs. compared to previous models.
“Dana continues to make progress in bringing about weight savings in our trailer suspension offerings,” said Mark Holley, product manager, trailer axle and chassis control systems. Holley identified the suspension’s trailing arm, cross members, and intercostals as the key areas where weight reductions were made.
ArvinMeritor, which manufactures a host of lightweight systems and components for tractors and trailers, also is the worldwide provider of LITEFLEX composite springs for commercial and specialty vehicle markets. LITEFLEX commercial vehicle composite springs, according to the company, are already offered as optional equipment on a number of Freightliner, Kenworth and International models and are being made available as options on tractors and trailers from a growing number of original equipment manufacturers.
Based on a monoleaf design and utilizing composite materials, Liteflex springs can help fleets haul heavier loads or save fuel when compared to conventional steel springs, according to ArvinMeritor. In some applications, Liteflex composite springs weigh as little as 40 percent of the weight of conventional steel springs, the company says.
Along with the weight savings possible from wheels, tires and suspensions, a large number of lightweight component options also are available on tractors and trailers. For example, ConMet aluminum hubs are used in many fleets as are Meritor X30 and Centrifuse brake drums, which can offer savings of 50 lbs. per tractor when including steer axles.
Other components spec’ed by fleets for weight savings include lightweight fifth wheels from suppliers such as Holland, Fontaine and Jost; and lightweight steer axles from ArvinMeritor and Dana Spicer. And in many instances, aluminum component options are popular. Choices include transmission housing, power divider sections in differentials, engine and transmission bell housings, rear axle carriers, cross members, suspension brackets and air tanks.
Fleet managers interested in reducing vehicle weight also will address items such as fuel tank capacity and the number of batteries required based on operational considerations. These changes often can help shed a few pounds, and in all cases lightweight means extra payload or fuel savings.
All things considered, spec’ing lightweight components is an effort worth undertaking.