Talk about aluminum lightweighting of vehicles tends to center on passenger cars and light trucks. However, aluminum has experienced more than 30 years of continual growth in commercial applications, driven largely by payload considerations.
The use of aluminum applications in commercial vehicles continues to rise steadily, with more than 65 percent of the tractor-trailer market adopting aluminum wheels today compared with 60 years ago, for example. The average Class 8 truck today uses more than 1,000 pounds of aluminum, and with additional emerging applications, vehicle weight could be reduced by up to 3,300 pounds. By exploring the advantages of lightweighting with aluminum, truck owners and operators can experience the real value and benefits a lighter vehicle has to offer, aluminum industry advocates say.
Overall, the amount of aluminum in vehicles is not only increasing, but also spreading across market segments and application types due to the many cost and fuel economy benefits that lightweight aluminum manufacturers claim to offer.
With growing pressure for more energy-efficient vehicles and lower operating costs, the trucking industry is dealing with demands for improved fuel economy, reduced emissions and additional increases in payload capacity.
Commercial trucks account for a growing portion of overall U.S. fuel consumption and, as such, represent a prime opportunity for lightweighting, said Doug Richman, vice president of engineering and technology at Kaiser Aluminum Corp., who also serves on the executive and technical committees of the Aluminum Associations Aluminum Transportation Group (ATG).
Total fuel consumption in the United States has doubled to 12 billion barrels of fuel per day from 6 billion barrels in the early 1970s, and commercial vehicles share of that total has grown to 25 percent from 15 percent, Richman said. For that reason, its become far more important to address fuel consumption in the heavy-duty truck sector.
The direct benefits of lightweighting trucks include a higher payload and reduced fuel consumption, according to Richman. The indirect benefits include reduced carbon dioxide (CO2) and particulate emissions, potentially lower maintenance costs and greater vehicle durability.
A transition to strong, affordable and carbon-reducing aluminum already is under way, which will enable cars and trucks to get lighter not necessarily smaller and more fuel-efficient. As (government agencies) have agreed, such a transition is a good thing both for consumers and the environment, Richman said.
In the commercial vehicle sector, the metal has made strides by allowing drivers to carry heavier loads per trip and lowering fuel consumption. The results showcase aluminums improvements in areas such as emissions, natural resources use, worker safety and training, and recycling.
The annual return on investment for materials substitution with aluminum on a single vehicle is estimated to be as high as 1,612 gallons of fuel and 17.9 tons of CO2. Downweighting with aluminum provides benefits not only to the environment but also to owners and operators, Richman said. A vehicle can yield fuel-economy improvements of 5 to 7 percent when weight is reduced by 10 percent. A 1-ton weight reduction with aluminum could save up to 3,400 gallons of fuel over the lifetime of a vehicle.
Reducing vehicle weight lowers fuel consumption, costs and greenhouse gas emissions, said Wade Long, marketing product manager for Volvo Trucks North America, a division of Sweden-based Volvo AB.
The European Aluminium Association recently released its Sustainable Development Indicators report, which examined the industrys efforts toward competitive, eco-friendly growth. The report said that aluminum-intensive trailers on the road in Europe are eventually dismantled directly on the continent and recycled at a very high rate. Current end-of-life processing practices were analyzed through four actual dismantling case studies, including a road tractor, a flatbed tractor-trailer, a silo tractor-trailer and a tipping body. The case study review suggested a minimum recycling rate of 95 percent in Europe.
Across the globe, the transportation sector is racing to revolutionize commercial vehicles with an eye toward improved performance. Whether it be faster acceleration or better cargo capacity, the challenge is to achieve these goals while reducing every vehicles footprint on the Earth.
The aluminum industry says it offers a simple solution: Lightweighting with aluminum allows vehicles to have increased fuel efficiency and produce fewer tailpipe emissions linked to climate change because they require less power to get around, making them the ultimate green vehicle.
The return on investment for downweighting with aluminum is even higher when combined with other improvements like aerodynamics, engine optimization and low rolling resistance, said Randall Scheps, ATG chairman and director of Alcoa Inc.s ground transportation market sector team.
The ATG said that aluminum use in commercial vehicles offers a number of benefits:
- Increased payload: Use of low-weight, high-strength aluminum components allows trucks to carry larger cargo loads without violating weight restrictions on bridges and roadways.
- Reduced fuel consumption: Aluminum use to reduce commercial vehicle weight increases fuel economy, leading to reduced fuel costs for operating the vehicle. Recent research shows that a 1-ton weight reduction can save up to 3,400 gallons of fuel over the lifetime of a vehicle.
- Reduced emissions: The increased use of aluminum in commercial vehicles reduces the overall weight of the vehicle, which significantly reduces the greenhouse gas emissions associated with global warming. As a result, truck owners and operators can reduce CO2 emission by 37 tons over the life of the vehicle and 32 life-cycle tons for every ton of aluminum added to a fleet.
- Lower maintenance costs: Increased payload capacity through lightweighting equals fewer trips and miles on the truck, ultimately saving maintenance costs associated with wear and tear on brakes and tire treads.
- Improved durability: Aluminum components are corrosion-resistant, which reduces the need for rust repair and increases the life cycle of the truck.
- Higher resale value: Commercial vehicles with aluminum components maintain their value, resulting in a higher residual value.
- Better recycling rates: Aluminum is one of the most recycled materials on the planet and is infinitely recyclable, meaning commercial vehicle aluminum applications never need to be landfilled.
To quantify the additional weight-savings potential aluminum offers to Class 8 vehicles, the Aluminum Association commissioned Ricardo Inc., a multi-industry consultant for engineering, technology, project innovation and strategy, to study the fuel efficiency impact of downweighting Class 8 trucks and trailers in the United States.
The study simulated different configurations of vehicles and payload conditions unloaded, gross vehicle weight (GVW) and half-GVW loadfor the major drive cycles that represent commercial transportation in the United States. In addition to the impact of weight savings alone, the study analyzed the combination of weight savings and aerodynamic drag reduction. The study concluded that significant freight and fuel efficiency, as well as emissions reduction, are available today with the appropriate use of lightweight solutions, such as aluminum.
Transporters using trucks that are downweighted might be able to carry 6.5 percent more payload per trip, which means fewer trips and an effective fuel and emissions savings of 6.5 percent. The annual return on investment for materials substitution with aluminum on a single vehicle is estimated to be as high as 1,612 gallons of fuel and 17.9 tons of CO2.
Strategic weight reduction with aluminum is a smart business tool that is rising in importance and recognized by truck and engine makers, as well as regulators, Scheps said. The use of aluminum opens an opportunity for the industry to increase fuel economy and efficiency to meet tough new regulations while providing companies with more profit through greater payload capacity, lower fuel costs, lower maintenance costs and higher resale value. Across the board, aluminum delivers like no other material.
When considering those results for the total U.S. fleet, estimated at 2 million vehicles, the overall economic and ecologic impacts of weight savings is estimated at as much as 1 billion gallons of diesel and 10 million tons of CO2 per year.
When combining the weight-reduction potential with an 8-percent improvement in aerodynamic drag, the overall fuel economy improvement for an aluminum-intense vehicle relative to a conventional vehicle is as high as 8.2 percent.
Based on other related studies and data on the benefits of aluminum, the ATG said it was able to make calculations related to life-cycle CO2 emissions and other improvements and benefits. While aluminum is a relatively energy-intensive material to produce, on a full life-cycle analysis basis, aluminum saves CO2. Ninety-five percent of the CO2 footprint of a truck occurs during the use phase of the vehicle, during which aluminum generates the largest savings. Including the CO2 generated in production, every pound of aluminum that replaces heavier steel saves a net 15 pounds of CO2 over the life cycle of the truck.
At last years Society of Automotive Engineers High Efficiency Heavy Duty Vehicles Symposium, Scheps discussed the benefits that aluminum provides the industry as it strives to meet first-ever fuel-economy regulations for commercial vehicles.
The regulations, announced by the Obama administration last fall and embraced by truck and engine manufacturers as well as environmental groups, identify aluminum above all other materials as having the greatest potential to safely reduce vehicle weight, boost fuel economy and cut CO2 emissions, he said. During his presentation, Scheps highlighted research findings that address aluminum weight savings benefits, including:
- Overall weight reduction: Aluminum has the potential to save up to 3,300 pounds on a vehicles weight. Specifically, substituting aluminum for roof cabs saves 60 pounds; cab floors, 56 pounds; frame rails, 435 pounds; cab rear walls, 49 pounds; and cab cross-members, 38 pounds.
- Fuel economy benefits: Weight reduction can yield a savings as high as 1,612 gallons of diesel fuel per vehicle each year, equating to nearly 1 billion gallons of diesel annually for the current U.S. fleet.
- Reduced CO2 emissions: Downweighting with aluminum saves up to 17.9 tons of CO2 emissions annually per vehicle.
The aluminum industry submitted comments on the National Highway Traffic Safety Administration (NHTSA) and U.S. Environmental Protection Agencys notice of intent to draft greenhouse gas emissions and mileage standards for heavy-duty trucks and buses for model years 2014-17. In its comments, the Aluminum Association cited research that indicates heavy-duty vehicle aluminum components can achieve a 2,360-pound (14 percent) reduction in typical tractor weight. Lighter vehicles use less fuel, making vehicle weight a key component in meeting the proposed standards.
EPA and NHTSA have done a good job in the difficult task of categorizing and developing an appropriate regulatory approach for each category in their first-ever effort to regulate the fuel economy for these vehicles. To meet the tough new fuel economy and emissions regulations being proposed, next-generation commercial vehicles will need to be lighter, cleaner and more fuel-efficient and aluminum delivers on all fronts, Scheps said.
He said that aluminum is the most environmentally friendly way to downweight a vehicle. Vehicles made lighter with aluminum produce fewer overall emissions and need less fuel or battery power to operate. And every pound of aluminum saves some 20 pounds of CO2 emissions over the lifetime of a vehicle. In fact, downweighting the worlds overall transportation fleet through the use of aluminum has the potential to reduce greenhouse gas emissions by 660 million tons annually, or nearly 9 percent of global, transportation-related greenhouse gas emissions.
Recycling aluminum saves nearly 95 percent of the greenhouse gas emissions associated with primary aluminum production. Nearly 90 percent of auto aluminum is recovered and recycled, and 73 percent of all aluminum ever produced is still in use today, the ATG said.
Independent analysis from a 2010 magnesium industry study conducted by the Magnesium Front End Research Development Project confirmed that aluminum has the smallest carbon footprint of competing materials when considering the full life-cycle of production, manufacturing, on-the-road use and end-of-life recycling. According to the study, magnesium delivers a 15-percent energy savings compared with steel, and aluminum yields a 20-percent energy savings. When considering total life-cycle CO2 emissions, magnesium is 12 percent better than steel and aluminum is 20 percent better, according to the study.
The aluminum industry has worked successfully to reduce its greenhouse gas emissions through voluntary initiatives and continuous technological advances. In the past 10 years, CO2 emissions have been reduced by 10 percent and perfluorocarbon emissions have been reduced by more than 80 percent compared with 1990 levels, the ATG said.