Making a car lighter is more difficult than you might think

The Center for Automotive Research investigates the barriers that stand between us and lighter, more efficient vehicles.

Andrew Krok Reviews Editor / Cars
Cars are Andrew's jam, as is strawberry. After spending years as a regular ol' car fanatic, he started working his way through the echelons of the automotive industry, starting out as social-media director of a small European-focused garage outside of Chicago. From there, he moved to the editorial side, penning several written features in Total 911 Magazine before becoming a full-time auto writer, first for a local Chicago outlet and then for CNET Cars.
Andrew Krok
2 min read

One might operate under the belief that making a vehicle lighter is easy -- just take some stuff out, or use a new metal engineered for lightness. But there are a whole host of factors standing in the way, from a risk-averse industry to basic human whims, and the Center for Automotive Research (CAR) is looking into them.

"Identifying Real World Barriers to Implementing Lightweighting Technologies and Challenges in Estimating the Increase in Costs" is the first in several studies meant to show that simple premises like "reduce emissions" and "improve fuel economy" are actually quite complicated.

The expansion of global platforms, for instance, means many parts are "overengineered" for use in multiple products, spanning both expensive and inexpensive vehicles. Established infrastructure means companies have already spent a great deal on existing technologies, and retooling entire plants and adopting new materials is both expensive and time consuming -- it's estimated that using a new material takes, on average, three to four years for qualification alone.

Then there's the matter of human whim. While the base body weight of a vehicle has dropped markedly over decades, desire for creature comforts and additional safety equipment has resulted in an increase in curb weight over the last 30 years, even though we're using fewer heavy materials (like iron) than ever before.

Graph: Car Mass over Time
Enlarge Image
Graph: Car Mass over Time

Pesky humans, with their needs and things.

Center for Automotive Research

This isn't even an easy topic to crack, as there are no convenient averages across the entire industry. With every car radically different than the next, despite sharing some or many similar parts, the study concludes "there is no single cost estimate (cost per pound) for lightweighting." Thus, every company attempting to do so is taking a risk that it can't necessarily grasp fully.

So, it's not as easy as Colin Chapman's "simplify, then add lightness" quote would have us believe. In fact, adding lightness is anything but simple.