Downweighting will be at the core of whatever other technology, design and powertrain changes are coming. Using aluminum will extend the efficiencies of other technologies, while enabling secondary cost-savings from downsized powertrains without sacrificing performance.

—Randall Scheps, Chairman of the Aluminum Association’s Aluminum Transportation Group and Marketing Director at Alcoa, Inc.

Aluminum is already the leading material in powertrain and wheel applications and the survey indicates it is quickly gaining market share in hoods, trunks, doors and bumpers. Body, bumper and closure content grew by 58% from 2009 to 2012, with 30% of all hoods on 2012 vehicles being aluminum, saving a total of 100 million pounds (45,359 tonnes) of vehicle weight across the entire fleet. Twenty percent of all bumpers in 2012 will be aluminum.

According to the report, future growth in auto aluminum usage will be primarily driven by these and other applications being converted from steel. For example, the trend line for aluminum hood penetration predicts a minimum share for aluminum of 41% by 2017 and 53% by 2025.

The survey also looked at average aluminum content by North American automakers, declaring General Motors the content leader at 366 pounds (166 kg) per vehicle. Honda leads aluminum content as a percent of curb weight at 10.7% in 2012.

The latest model vehicles featuring above average aluminum content (more than 9% of vehicle curb weight) include the Chevrolet Malibu, Cadillac CTS, Ford Explorer, Ford Focus, Ford Escape, Lincoln MKZ, Chrysler C sedan, Honda Civic/CR-V, Honda Accord, Nissan Altima, Toyota Avalon and Fiat 500.

On a segment basis, the survey points to future growth areas in mid-size and large sedans as well as full-size full frame vehicles (i.e. light-duty pick-up trucks) mainly due to the comfort, safety and functionality requirements expected from the customer.

A material mix shift is necessary to achieve a 10% weight reduction for light vehicles and 51 mpg US. Ducker Worldwide. Click to enlarge.

As automakers apply aluminum to reduce the weight of their vehicles, the focus is increasingly toward the system cost, which allows aluminum to compete successfully with other materials because of the advantages it brings in primary and secondary weight savings, fuel savings, structural performance and design flexibility. Secondary cost savings that come from using automotive aluminum can offset cost premiums helping make aluminum a more cost-effective solution, according to the report. The report estimates the cost of the materials upgrade at less than $500, even before secondary cost savings from downsized components are factored in.

Other highlights from the report include:

• The average increase in aluminum content since 1975 has been 7 lbs (3.2 kg) per year per light vehicle.

• Automakers will, on average, seek to lower the weight of cars and light trucks by at least 10% by 2025.

• Market factors already in place are projected to push aluminum content to 400 pounds per vehicle in 2015/2016.

• Aluminum is gaining market share at the expense of both traditional and high strength steels (HSLA), which are declining as a percentage of vehicle makeup.

• Advanced High Strength Steels (AHSS) also are growing at the expense of inferior steels, but gauge reduction with AHSS provides limited weight savings potential compared to using lower density aluminum. Pound for pound, aluminum replaces more than twice as much weight as AHSS.

We are fast-entering a transition stage to more holistic vehicle design approaches premised on greater use of lighter, stronger and more crash absorbent aluminum alloys replacing less efficient iron and steel. Vehicles with their size maintained, but downweighted with aluminum are inherently more efficient than heavier ones.

Most importantly in this holistic approach, downweighting is actually an enabler of cost savings across the vehicle by accommodating downsized powertrains and parts consolidation—all without sacrificing safety or performance. A lighter car can allow for a smaller, less expensive drive train and generate the same performance as the original vehicle…more cost-effectively, safer and most importantly in a more fuel efficient manner.

—Randall Scheps

Resources

• Aluminum in 2012 North American Light Vehicles Executive Summary