Rubens Barrichello's Williams clocked the fastest time during Formula One's second pre-season test in Jerez, Spain.

All teams apart from Hispania Racing were able to get laps into the 2011 cars in Jerez, with Barrichello's Williams overcoming several problems earlier in the four-day test to head their rivals at the end of Sunday's final session.

The Saturday had seen Nick Heidfeld impress as he was given the chance to shine in the new Lotus Renault R31.

The German is looking to secure the vacancy left by Robert Kubica's serious rally crash less than a fortnight ago.

Bruno Senna was also given time in the Renault R31 – the team backed by Hethel's Group Lotus.

As for Hingham's Team Lotus, Heikki Kovalainen posted Sunday's sixth quickest time, while Saturday gave the Finn a chance to test the team's moveable rear wing – a downforce reduction system (DRS) introduced by Formula One with the view to increase overtaking at the end of the start-finish straight.

All teams are trying to get to grips with the new system and produce reliable and effective technology to make the stalled rear wing work.

Kovalainen said: 'I really enjoyed driving the car. I still have the same feeling that I had in Valencia – it's fundamentally a good car and there's a lot more to come from it.

'We tried the DRS in race mode and even though I had thought the procedure to initiate it might be pretty complicated it actually all worked easily. Once you get used to it the system is pretty simple.

'I used it in both race and practice mode and it returns to position well so I have no problems under braking and am very happy with how it all works. By the time the day ended we finished right in the mix so we're all pretty happy with the day's work.'

Team Lotus sporting director Dieter Gass added after Sunday: 'The car does look quick and we have a very good platform to work on.'

• Sunday's fastest test times in Jerez: 1 Rubens Barrichello (Williams) one minute 19.832 seconds, 2 Kamui Kobayashi (Sauber) 1:20.601, 3 Fernando Alonso (Ferrari) 1:21.074, 4 Sebastien Buemi (Toro Rosso) 1:21.213, 5 Bruno Senna (Renault) 1:21.400, 6 Heikki Kovalainen (Team Lotus) 1:21.632, 7 Nico Rosberg (Mercedes) 1:22.103, 8 Sebastian Vettel (Red Bull) 1:22.222, 9 Jenson Button (McLaren) 1:22.278, 10 Jerome D'Ambrosio (Virgin) 1:22.985, 11 Paul Di Resta (Force India) 1:23.111.