Lewis Hamilton gave Mercedes rivals a taste of the true pace of the team’s new W04 car as he topped the Barcelona timesheet with a lap almost seventh tenths of a second clear of second-fastest man Felipe Massa.

With the weather in Barcelona much improved overnight, Hamilton was quick to take advantage and spent the morning lighting up the timing screens with a sequence of short runs that by the lunch break left him with a time of 1:20.558 set on soft tyres.

“The reliability, the mileage and the step-by-step improvements that we have achieved during the three tests are all very encouraging."
Lewis Hamilton

As the afternoon progressed Hamilton’s rivals edged closer to his time, but by the end of running the time still stood, with Ferrari’s Felipe Massa the only driver to get within a second of the Mercedes driver’s benchmark.

“It was great to have a dry track today for my final day of testing, and we were able to get through all the test items that we wanted to achieve by the end of my programme,” said Hamilton afterwards. “The reliability, the mileage and the step-by-step improvements that we have achieved during the three tests are all very encouraging. Whilst we've been focusing on our own performance, we definitely haven't seen the full potential of our competitors yet, so it's difficult to predict where we might be.”

Massa’s time of 1:21.457, scored midway through the afternoon, was set on super soft tyres. However, 20 minutes from the end of the session the Brazilian was forced to stop on track after his front-left wheel detached. Ferrari later said a broken front upright was at fault for the stoppage.

Force India’s Adrian Sutil claimed the day’s third-quickest time. The German spent most of the morning on pit stop practice and installation laps, but in the afternoon strapped on Pirelli’s super soft tyre for some performance runs, which netted him a lap of 1:21.627. After a sequence of short runs, Sutil then switched to long runs for a race simulation.

The Williams duo of Pastor Maldonado and Valtteri Bottas claimed fourth and fifth places respectively, with the Venezuelan running in the morning and the Finn taking over after lunch.

With Esteban Gutierrez sixth for Sauber, seventh place went to Mark Webber. The Australian’s final day of testing was a frustrating one, however, as overnight changes to the RB9 meant a late start to his morning runs. A long spell in the garage over lunch for more changes then meant Webber didn’t appear on track until 3pm. As such his tally of 59 laps was the lowest team total of the day.

“I would obviously have liked to get a few laps in today, but that’s the way it goes sometimes in testing,” Webber said. ”We had a few small issues with the car today which delayed us a couple of times and while it wasn’t ideal I think we still learned plenty.

“In terms of the overall feeling at the end of my spell of testing, I think we’ve done well and we have made a step forward. As I’ve said before it’s very difficult to see a real pecking order. We’ve just always been focused on what we have to do and not really looked too hard at anyone else. The important thing now is just to get out to Melbourne and get on with the racing. We have some work to do, for sure, and we have a few things we need to iron out, but that’s the same for everybody.”

Behind Webber, Sergio Perez was eighth for McLaren, while Jean-Eric Vergne set the day’s ninth-fastest time for Toro Rosso. They were followed by the Lotus pairing of Romain Grosjean and reserve driver David Valsecchi.

Valsecchi had been promoted to the cockpit first thing in the morning when Kimi Raikkonen was forced to abandon driving duties due to illness. Grosjean, meanwhile, was forced to fly to Barcelona from Paris to take over at the wheel in the afternoon.

“This morning was quite a rush to get everything ready as the call only came late, but the team were fantastic getting the car prepared for me,” said 2012 GP champion Valsecchi. “I only completed short runs today so I have a limited impression of the E21, however it’s clear that it’s a very good racing car. For me to be able to get immediately on the pace means that the car is certainly fast and competitive. It was a fantastic opportunity; I sat in the seat of a former world champion so I knew that I’d be fast for sure.”

Lotus later said that if well enough Raikkonen will return to the Circuit de Catalunya tomorrow for a final pre-season day at the wheel of the E21.