DETROIT -- Through a mix of lighter materials and fewer components, Lotus Engineering was able to show how a body-in-white could be almost 40 percent lighter with no increase in cost.
In a yet-to-be-published study commissioned by the California Air Resources Board, the British engineering consulting firm, an affiliate of the sports car maker, shows that automakers can reduce vehicle weight and increase fuel efficiency by focusing on the body-in-white, Lotus Engineering's North American head Darren Somerset told Automotive News last week.
Using a Toyota Venza, the company was able to make the body-in-white 36 percent lighter, Somerset said. Lotus replaced the standard steel frame with a body-in-white made of magnesium, aluminum, high-strength steel and composite materials. But production costs rose by 50 percent because of more expensive materials.
The firm offset those costs by eliminating some components and making others perform multiple functions. The body-in-white started with more than 400 parts, but Lotus cut that to fewer than 170.
CARB plans to use the study results to try to convince automakers that reducing weight is an effective way to make vehicles more fuel efficient. Somerset said a 10 percent reduction in weight increases fuel efficiency by 6 to 8 percent.
"It's a very powerful message that it is possible to reduce mass on a vehicle in a cost-effective manner if you approach it in a holistic, system level," he said. "If you just swap out heavier material with lighter material at a component level, the cost spirals out of control and you don't have a business case that is palatable."
The study for CARB is the second phase of Lotus' research in this area. In results released last month, Lotus found that reducing the weight of a vehicle by 38 percent, assuming an annual sales volume of 50,000 units, would slash that vehicle's fuel consumption by 23 percent and increase manufacturing costs by only 3 percent.
