KERS ‘not big advantage’ – Heidfeld
Team boss Mario Theissen said earlier this week that, for Barcelona, it was a case of opting either for keeping the energy re-use technology, or installing a major aerodynamic update.
"The tuning time on Friday would be too short," he said, amid reports that the KERS batteries simply did not fit into the new sidepods of the F1.09.
"We may come back to KERS in Turkey. From a technical point of view, the results are positive. The (KERS) system has worked flawlessly up to now," he added.
But to reporters in the Circuit de Catalunya paddock, German driver Heidfeld gave a different account.
"We have found that KERS is not yet as large an advantage as we thought," he is quoted as saying by the German news agency SID.
Now without KERS, it remains to be seen whether the team leaves its 'Active Hybrid' signage on the rear wing this weekend.
After a mainly uncompetitive start to the season, Heidfeld admitted his fingers are crossed that recent efforts in the Hinwil factory will bear fruit in Spain.
Referring to the upgraded package, the 31-year-old said: "We hope we see on the track what we saw in simulation and in the wind tunnel."