Lightweight chassis propels EV development at Lotus

Developed under Project LEVA (Lightweight Electric Vehicle Architecture), the adaptable frame can support multiple vehicle configurations, including two and four seaters, different wheelbases, and a variety of battery sizes and layouts.

According to Lotus, the rear structure of the chassis – made from high-strength BD1 aluminium developed at Brunel university - is 37 per cent lighter than it is on the Lotus Emira V6, a £60k sports car launched this summer by the Hethel-based carmaker and the last of its offerings with an internal combustion engine.

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Project LEVA has been led by engineer Richard Rackham, head of Vehicle Concepts at Lotus, who is best known for his work on development of the extruded aluminium Lotus Elise architecture 25 years ago.

“Project LEVA is as revolutionary now as the Elise architecture was in 1996,” Rackham said in a statement. “In true Lotus spirit, significant weight savings have been achieved throughout, with a focus on ultimate performance, efficiency and safety being engineered into the structure from the outset – for example, by utilising the vehicle structure as the battery enclosure, having an integrated EDU, eliminating subframes and optimising the multi-link suspension components.”

Two-seater versions of the new chassis can be laid out with either an eight or 12-module battery pack in a ‘chest’ configuration behind the cabin, with the four-seater chassis featuring an eight-module battery in a ‘slab’ format that lies horizontally beneath the cabin.

The new subframe will feature cylindrical battery cells for high energy density, with the option of a single or twin electronic drive unit (EDU), depending on the configuration. Lotus claims that the flexibility and modularity in wheelbase, battery and powertrain will facilitate a wide variety of electric vehicles, the first of which is slated to launch in 2026.

The chassis will also be available commercially to third parties via Lotus Engineering. Part of the funding for Project LEVA was delivered via the Advanced Route to Market Demonstrator programme (ARMD), run by the UK government’s Department for Business, Energy and Industrial Strategy (BEIS).

“Today’s EVs are heavy in comparison to their ICE equivalents, so the ARMD funding has helped Lotus to innovate earlier in the product cycle and develop a new vehicle architecture that targets lightweight and performance density from conception,” said Richard Moore, executive director of Engineering, Lotus Cars.

“Rather than developing a single vehicle, it means Lotus now has the ‘blueprint’ for the next generation of electric sports cars, for future Lotus products and for the Lotus Engineering consultancy to commercialise.”