A lightweight Lotus chassis

A lightweight Lotus chassis

Lotus founder Colin Chapman was perhaps best known for his ability to “add lightness” to purpose-built race cars. Legend has it that Chapman would only stop removing bracing from a race car chassis when he approached (or sometimes exceeded) the point of structural failure.

Lotus may not go to these extremes any longer, but the company knows a thing or two about designing lightweight cars. For a price, it’s willing to share this knowledge and consult with other automakers on shaving pounds from a vehicle platform, providing as much engineering and development assistance as a partner company needs.

A soon-to-be-published report, previewed by Automotive News (subscription required), documents the steps that Lotus went through to reduce the body-in-white weight of a Toyota Venza by some 38-percent.

Step one involved replacing some of the Venza’s unibody steel with magnesium, aluminum, high-strength steel and composite materials. As expected, this increased the production cost by 50-percent, unacceptable to a mainstream vehicle manufacturer.

To bring costs back in line, Lotus looked at every component used in the Venza’s body-in-white, and eliminated parts wherever possible. The net result was a reduction from 400 components used to just 170, a reduction of over 57 percent.

The study was funded by the California Air Resources Board (CARB), who’ll use it to illustrate what’s possible through lightweight engineering. CARB estimates that a 10-percent reduction in vehicle weight can increase fuel efficiency by as much as eight percent, but we’d argue that other factors (such as driving style) play an equally important role.

Of the exercise, Lotus Engineering North America head Darren Somerset said, “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.”

According to Lotus’ own data, reducing a vehicle’s weight by 38-percent, with an annual production volume of 50,000 units, could reduce fuel consumption by 23-percent while increasing manufacturing costs by just three percent.

Will consumers pay $1,000 more for a Toyota Venza that delivers over 33 mpg on the highway? Both Lotus and CARB are betting the answer to that question is yes.