Team Lotus has confirmed reports that the 2011 car does not feature a KERS system.
We reported recently that HRT and Virgin will also be starting the forthcoming season without the energy-recovery technology.
"The decision made the design job slightly easier, because packaging it in the car is always a bit more of a headache," chief designer Lewis Butler said in the Team Lotus Notes magazine.
Confirmed head of aerodynamics Marianne Hinson: "It's the same for us in aerodynamics -- no KERS is actually easier because packaging all the bits you need for it is actually quite limiting for some of the aero shapes you need in some areas."
Lotus is not ruling out installing KERS at a later date, but chief operating officer Keith Saunt suggested it is not necessary for the team to take its next step.
"If KERS was going to get us from eighth to sixth then we'd have it," he said. "But when you look at the weight of it and some of the engineering challenges, I think it's a good decision not to start with it.
"We might end up with it, who knows?" added Saunt. "But if we did we've got a lot of experienced people who could turn their hands to it."