Mark Webber says his Red Bull Racing team remains unsure if it will race with its F-duct system in the European Grand Prix this weekend.
Both Webber and teammate Sebastian Vettel tried the system during today's practice session, but the Australian admitted a decision is yet to be made, with the decide posing challenges to the team to get it working properly.
"We need to look at it more," said Webber after posting the third-quickest time of the day. "It is not without its challenges, so I'm not sure if we will race it yet. It's better, but whether it's good enough we will see."
Webber said he was pleased with his day's work and reckons Red Bull will be strong in Valencia, although he admitted he is not expecting the team to be able to dominate.
"It was a good day, actually," he said. "We evaluated the F-duct which we will look a bit more into tonight. We know it is not without its challenges getting the thing working, so there will be more research tonight going into that.
"The track changed a lot this afternoon so the conditions were moving around quite a bit. In the end it was a pretty good day. The car ran faultlessly, and it felt pretty comfortable so I am looking forward to tomorrow."
He added: "We look OK. We are not killing people but we are going OK. Many people are trying new things at this race, and so are we, so it's a good fight."