April 18th, 2013 (GMM) The secret of Lotus' speed in 2013 is an hydraulically-controlled active suspension system, Germany's specialist Auto Motor und Sport reports.
Last month, we reported that, under the skin of Mercedes' new W04 car, a system known in the German squad's garage as 'Fric' was legally mimicking otherwise outlawed electronic active suspension.
Auto Motor und Sport reports that it is Mercedes engineers who therefore believe they have uncovered the secret of how Lotus' E21 is looking after Pirelli's highly-degrading tyres so well in 2013.
"We believe that their integrated chassis (system) is working best of all," said Mercedes' Aldo Costa.
Auto Motor und Sport said not only Mercedes, but also Red Bull, McLaren, Ferrari, Williams and Sauber have been working on similar technology.
It links the four corners of the car hydraulically, balancing the car during braking and accelerating, and adjusting the balance as the fuel load lessens during a race.
Mercedes team boss Ross Brawn admitted: "Lotus has the simplest, but probably the best system."
The news could also explain Romain Grosjean's struggle versus Kimi Raikkonen so far in 2013.
Auto Motor und Sport correspondent Michael Schmidt said the 'Fric' systems are notoriously difficult to tune.
Lotus team owner Gerard Lopez admits: "The suspension tuning window is very small, and we get it right more often with Kimi than with Grosjean."
This is due to the drivers' respective driving styles, with Frenchman Grosjean reportedly preferring understeer to Raikkonen's oversteer.