New Study Separates Effects of Size and Weight on Vehicle Safety

Study Says Larger, Lighter Vehicles Improve Overall Safety

A new study released today by The Aluminum Association Inc. shows injuries in crashes involving SUVs can be reduced up to 26 percent by using aluminum or other high-strength, lightweight materials in the vehicle design and adding slightly longer energy-absorbing crush zones. The end result improves vehicle safety and compatibility.

The study, conducted by Dynamic Research Inc. (DRI), was unveiled during a presentation to the Washington Automotive Press Association. The study evaluated how crashworthiness and crash compatibility would be affected if a vehicle's weight was reduced or remained constant, but its size was maintained or increased. DRI modeling studies have been used by the National Highway Traffic Safety Administration (NHTSA) in its research.

"This groundbreaking study, using computer simulations, allows us to quantify the relative safety benefits of large vehicles compared to heavy vehicles. What the data tells us is that high-strength, lightweight materials like aluminum can be used to improve an SUV's crashworthiness, and better protect its occupants and the occupants of smaller vehicles in a crash. Everybody wins," said Tom Gannon, chairman of the Aluminum Association's Auto and Light Truck Group.

The study results are timely given continually rising fuel costs, as well as ongoing concerns regarding vehicle safety and SUV compatibility in crashes with smaller passenger cars. The aluminum industry commissioned the study in light of potential changes to the structure of the Corporate Average Fuel Economy (CAFE) program that NHTSA is considering.

"Depending on the specific approach pursued, NHTSA's forthcoming proposal to restructure the CAFE program for SUVs, pickups and minivans could inadvertently create disincentives for use of innovative tools, technologies and lightweight materials by automakers. Our goal is to ensure no artificial barriers are created that could potentially take innovative solutions linked to high-strength, lightweight materials out of the hands of the carmakers," said Gannon.

Continually working to improve vehicle fuel efficiency and reduce emissions, automakers can achieve these safety and fuel economy advances through smart engineering and using high-strength, lightweight aluminum in the vehicle design and manufacturing process. This vehicle development process is already found on aluminum intensive cars today, such as the five-star safety rated Audi A8, considered by many to be the safest vehicle on the road today, and the reengineered Jaguar XJ.

"In addition to performance and design benefits, a big reason for aluminum's continued growth is its ability to reduce weight or offset the weight of added safety and consumer features, thereby maintaining or even increasing fuel efficiency," said Gannon. "This new study confirms that carmakers can continue to provide their customers with great performing cars and outstanding fuel economy, while still maintaining the highest possible safety standards."

Specifically, the study's objective was to quantify how crashworthiness and crash compatibility with other vehicles would be affected with a slightly redesigned SUV. One aspect of the study reduced the SUV's weight by twenty percent, but kept its size the same. Another aspect extended the same SUV's front and rear crash zones by about four and one-half inches total without changing its weight. The aluminum industry believes manufactures would do a little of both -- cut weight and use some of the weight saving to improve the vehicle safety by expanding the front and rear crumple zones.

Using real-world information from NHTSA's crash databases, the study's crash scenarios were selected to represent the national average for moderately severe collisions -- meaning that at least one of the vehicles was towed away. Five hundred (500) collisions were simulated with DRI's advanced computer modeling programs. Injury estimates were based on ISO standard 13232.

Aluminum is currently the third most-used material in automotive construction, behind only steel and iron. For model year 2002-2003, the average vehicle contained 274 pounds of aluminum; cars contained 267 pounds of aluminum on average, and light trucks contained 279 pounds on average. It is generally accepted that a six to eight percent fuel savings can be realized for every 10 percent reduction in a vehicle's weight, and improved fuel economy reduces green house gas emissions. An additional environmental advantage is aluminum's recyclability: nearly 90 percent of automotive aluminum is recovered and recycled.