Lewis Hamilton admits he is yet to find the optimum set-up in Spain despite leading the qualifying simulations by four tenths on Friday.
Hamilton has scored four consecutive pole positions this season and looked comfortable over one lap when the option tyres were bolted on in FP2. He had seven tenths in hand over Mercedes team-mate Nico Rosberg in third place but, despite a positive session, Hamilton feels there is still a lot more to come from the car.
"At the moment I'm not," he said when asked if he was happy with the balance of the car. "I don't really know why. It feels very inconsistent throughout the lap, because I think the wind is up and down. In some places you're getting gusts, sometimes you're not getting a gust. Sometimes it's oversteer, sometimes its understeer. Sometimes it's fine, perfect, then the next lap it's different, so that makes it very difficult to find the set-up."
Hamilton said it is not unusual to struggle to find an optimum set-up on Fridays in Barcelona.
"I don't know if there is less grip, because this is what we started with today - it's like Melbourne. It's definitely harder to drive because sometimes the car's perfect, sometimes it's understeer, sometimes it's oversteer, so it's actually really hard."
Hamilton is yet to lose to Rosberg in qualifying or a grand prix this season but the world champion is refusing to write off his team-mate.
"I think he's going to be quick. I just need to be quicker."