When it comes to cars, weight can be the enemy. A lightweight car accelerates faster, handles better, and uses less fuel — the reason Audi has dedicated its Aluminum and Lightweight Design Center in Germany to tackling the problem.
It isn’t the only automaker working on lightweight technology, but it’s a leader in the field. Its aluminum Audi Space Frame construction, currently found in the A8, R8 and TT models, has been an essential tool for 15 years. Last year alone, the company applied for 38 lightweight patent designs.
“In 1982, lightweight design became part of our philosophy,” says Heinrich Timm, head of the Design Center. “We are facing global trends, such as fuel prices, transportation and infrastructure. The components of electric and hybrid vehicles are heavy, and will require lightweight technologies to balance them.”
Building a lighter car isn’t as simple as just making a steel part out of aluminum. Audi must consider how to shape and fasten the material, if it can be reliably sourced and volume-built, and if it lends itself to assembly-line production. Reducing weight on one part of the car requires balancing it elsewhere. Cost also becomes a factor: much of Audi’s cutting-edge technology is found on its priciest models, since these new materials are still very expensive.
The designers also remove anything that isn’t necessary. “Use the best material at the right place, and as little of it as possible,” Timm says.
The company took its cues from nature: bird bones and elephant skulls are hollow, braced inside with just enough bone to provide vital support, and Audi builds parts the same way. In crash testing, a thin-walled aluminum strut with interior bracing stands up better than a thick-walled piece of steel, and is a fraction of its weight.
Not everything at the Center goes straight to the assembly line, but each project yields new insight. The company shows a “hybrid” brake disc, so-called because it combines several innovative materials. It’s a fraction of the weight of a conventional one, but far too expensive and difficult to manufacture for volume production. Still, its design has led to a new pin connector that improves a regular brake disc’s performance, which Audi is working on integrating into its vehicles.
Nothing is too small to be considered: even grams of weight add up. “We want the lightest and strongest body at a proper cost,” Timm says. “Sporty, progressive and sophisticated: this is the principle of Audi.”
