Using lighter materials, Lotus Engineering recently showed how the body of a car could be made up to 40 per cent lighter without adding cost. A study made by the California Air Resources Board is not yet published, and the British engineering consulting firm, an affiliate of the sports car maker, explained that automakers can decrease vehicle weight and increase fuel efficiency by concentrating on the ‘body-in-white’. Body-in-white means the stage of car production when the body of a car is almost bare with only sheet metal components welded to the frame and a body yet to be painted.

Using Toyota Venza — a crossover vehicle in the US, Lotus was able to make the body-in-white 36 per cent lighter and also replaced the standard steel frame with a body-in-white made of magnesium, aluminum, high-strength steel and composite materials.

But, the production costs increased to 50 percent due to the expense of materials.

Lotus however, compensated those costs by cutting 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.

“A 10 percent reduction in weight increases fuel efficiency by 6 to 8 per cent. 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. If you just swap out heavier material with the lighter material at a component level, the cost spirals out of control and you don’t have a business case that is palatable,” said Darren Somerset —Lotus Engineering’s North American boss.

The study made by CARB is actually the second phase of Lotus’ research and the already published results says that if you decrease the vehicle’s weight by 38 per cent, on annual sales of 50,000 units, fuel consumption would fall by 23 per cent, with only a 3 per cent increase in overall costs.

via Caradvice