Lewis Hamilton may have been the pacesetter in Practice for the Spanish Grand Prix but he’s still not happy with his performance.

The reigning champion believes he still has work to do in order to improve his Mercedes car ahead of Qualifying. Nico Rosberg was faster in the first session with Hamilton taking the second, so Mercedes appear to still hold an advantage despite the three week break promising upgrades for all teams.

Hamilton is chasing a fourth win from five, and described his win in Bahrain as "fairly decent". However the windy conditions at the Barcelona circuit mean it was difficult for Hamilton to decide on a set-up strategy.

"The wind is up and down so sometimes you’re getting a gust and sometimes you’re not getting a gust. Sometimes it’s understeer, sometimes it’s oversteer. Sometimes it’s fine and perfect and then the next lap it’s different. So that makes it very difficult with the set-up," the world champion said.

It appears Ferrari will continue to be the main threat to Mercedes in Spain, with both Sebastian Vettel and Kimi Raikkonen eager to spoil Lewis’ attempts of a fifth pole from five this season. However it appears Hamilton is more wary of team mate Rosberg than the Scuderia. "I think he’s going to be quick, so I’ll try and be quicker," Lewis said rather abruptly.

Rosberg appeared encouraged by his long run pace compared to that of the Ferrari duo and Hamilton. The German said: "It’s just some small problems, we need to fine-tune some of those things. We were trying some new settings on the downshifts and that meant when I was pulling for the downshifts there was a delay, it didn’t go in straight away.

All in all it was a good day, I have to say for the race especially. It was looking pretty good, especially compared to Ferrari which is important and compared to Lewis it was close. On one lap I still have some work to do," he added.