Romain Grosjean underlined the competitiveness of Hethel-backed Lotus on day two of the Formula One test at Mugello, but had to share the honour of fastest lap time with the Sauber of Kamui Kobayashi.

Tuesday's opening running had been heavily affected by rain but after a damp start the teams were able to take full advantage of a dry track on Wednesday, with Grosjean setting the time to beat by lapping the Italian track in one minute 21.603 seconds.

The Frenchman's performance suggests the pace the team showed in picking up a double podium in Bahrain was no fluke, although his time was equalled by Kobayashi during the dying embers of the day.

World champion Sebastian Vettel and team-mate Mark Webber shared the running for Red Bull, with the German's afternoon time proving marginally quicker than that managed by the Australian in the morning as they finished third and fourth.

Grosjean said: 'It's always good to end the day on top, but we have to remember that in testing, lap times mean very little.

'Having said that, the car felt great and I was very comfortable from the start. This test gives us an opportunity to try things we wouldn't have time to do during a race weekend, so hopefully it'll help us to keep pushing forward.

'We've done a lot of set-up work today, and for sure we'll need to take some time to look through all the data and analyse what we need to focus on tomorrow, but it's a good baseline for the final day.'

Hingham's Caterham saw Attleborough racer and test driver Rodolfo Gonzalez in the seat for Tuesday before Vitaly Petrov took over the reins on Wednesday. The Norfolk marque have been busy testing new exhaust configurations as they bid to close the gap on F1's midfield.

Caterham engineer Jody Egginton said: 'Day two in Mugello has been a good one for the team. With Vitaly in the car we managed to complete 112 laps…from that we have generated a very good amount of data the team on track and back at the factory can use to accurately assess what we have gained with the updates, which include new bodywork, rear wing and a look at a revised exhaust layout.'

Heikki Kovalainen steps into the CT01 for Thursday's final test session.