Lewis Hamilton: "It was very slippery out there today. In P2, the grip was a little lower because the new Prime tyre proved a bit tricky to switch on. But once we fitted the Option tyre, it was much easier to drive and we seemed to have some pretty decent pace.

"There are still plenty of improvements we can make to the car. We need to work on the balance; it's not a million miles away, but it could be better. There are some things we'll change this evening to make it more stable.

"It looks very tight up at the front but we're definitely in the fight, which is the important thing. I think we've got some more pace up our sleeves for the rest of the weekend, too."

Jenson Button: "This morning we were mainly collecting data, so I spent quite a lot of time in the garage. In the afternoon, I did a bit more running and tried both tyre compounds. The Prime proved quite difficult to switch on, and consequently we couldn't find good balance with it.

"I think we've got a good balance on the Option though - and, because the track will grip-up quite a lot with every session we run, we're now heading in the right direction balance-wise with the Prime too.

"I wasn't paying too much attention to the times today, as it was more important to work with our engineers to get the car working on both sets of tyres. But, as I say, I think we've found a positive direction now."

Martin Whitmarsh, Team Principal: "This was a typically busy test day for the Vodafone McLaren Mercedes team. The morning's session's focus was primarily on gathering data - not just for this weekend but for future races too - and the results were both productive and encouraging.

"Whilst we were finding it quite difficult to switch on the Prime - both Lewis and Jenson were unable to achieve a truly satisfactory balance with it - it was encouraging to note our pace once we switched to the Option, on which we looked immediately competitive.

"The challenge for our engineers tonight will therefore be to successfully achieve a set-up that balances both compounds. Overall, then, we feel comfortable with the direction we established today."

To check out our Valencia practice gallery, click here.