McLaren duo set the pace in Bahrain

The Spaniard set a time of 1:30.994, just one tenth of a second faster than Hamilton, with the Ferrari pair of Felipe Massa and Kimi Raikkonen a further seven tenths behind.

The Brazilian and Finnish drivers carried out long run tests for Ferrari's 056 engine, the team stating they covered more than double a race weekend distance - which also included a Grand Prix simulation with pitstops, various set-up changes and a comparison of various mechanical components.

Today's test session was held under partly cloudy skies and warm temperatures at the Sakhir track, with all teams but Williams and Spyker taking part in the running.

The day began with Toro Rosso's Scott Speed bringing the session to a stop as he spun off an hour into the running, but he avoided damage to his car and was later able to continue, finishing the day last on the timesheet.

Toyota's Jarno Trulli, who ended only just ahead of Speed, brought out the second red flag at noon, when his car stopped on track, followed shortly after by Raikkonen, who suffered a gearbox failure.

Commenting on his day, Trulli said: "The positive thing from today was that we did a lot of miles, almost twice a race distance, and this should be very helpful to us.

"Unfortunately my lap times were not that good but that was more because we were concentrating on long runs rather than qualifying simulations.

"It has been a reasonable day and the laps I did helped us evaluate several things on the car, including our new aero package."

After lunch, Alonso too had to stop on track, with oil dripping from the floor of his MP4-22. Hamilton also stopped on track an hour later with an engine failure.

At the end of the day, Alonso commented: "It has been interesting to get the MP4-22 on track in the consistent weather conditions of Bahrain.

"We have been able to get a fuller understanding of the car and how it works in the warmer temperatures, including looking at areas such as the cooling system, which has been productive.

"It was a chance for me to see the latest performance upgrades, and we have useful feedback from the developments that have been incorporated.

"It was great to see some of the work that has been done on the test track and at the McLaren Technology Centre on the car, as we progress towards Australia.

"We have another three days next week in Bahrain and have to make the most of that time. There is, as always in Formula One, still work to do."

The technical gremlins also affected BMW Sauber, with Nick Heidfeld's engine blowing after lunchtime, while teammate Robert Kubica's car had an oil line problem that resulted in an engine change.

Nevertheless, the Polish driver was able to complete his programme, testing various damper settings and new aero parts, which the team said had brought positive results. Heidfeld and Kubica finished the day as 10th and 11th fastest respectively.

Honda's Jenson Button, seventh overall, also saw an engine change, as did Red Bull's David Coulthard, who also had his gearbox changed in the RB3. Coulthard was eighth fastest, with teammate Mark Webber only 14th.

Button's teammate Rubens Barrichello had a productive day, running the most laps of all drivers with a total of 129, and setting the sixth fastest time.

"It's been a good week in Bahrain for us and we have completed all the mileage that we had planned," the Brazilian commented. "The car proved reliable and it also seems to work well in the hot temperatures so we have been more competitive here.

"We have still got some fine-tuning to do on the car as the balance is not quite there yet, so next week's test will be important to help us resolve this before the season starts."

Super Aguri's Anthony Davidson was also showing consistency, accumulating a total of 126 trouble-free laps in the interim car.

"It has been a positive test for the team and we have continued to learn about the new Bridgestone Potenza tyres," Davidson commented.

"It was interesting having two different compounds here, and we found good car balance with both types. I feel that we have been competitive with our lap times, especially on the longer runs, and with the reliability of the car.

"As the track grip improved it seemed to suit the car more and more, and this gives me a good indication of rubber levels that we will see over the race weekend."

Also running over a hundred laps were test drivers Nelson Piquet Jr for Renault and Franck Montagny for Toyota. Both finished ninth and 13th fastest, respectively.

Christian Silk, Renault's chief test engineer, summed up the team's three-day session in saying: "Our car has been very reliable, and the car has responded well to the different set-up options we have studied this week.

"Both drivers were very focused for all three days. For Heikki, it's an advantage to gain further experience on the circuit where he will compete in his third Grand Prix.

"As for Nelsinho, it was a good chance to work with the  race team. We have had some encouraging results this  week, and we will look to build on them next week with Heikki and Giancarlo."

Dieter Gass, Toyota's chief engineer, stated at the end of the day: "We wrapped up the first part of the Bahrain test in a positive way, putting a lot of miles on both cars without major problems.

"We had a planned engine and gearbox change over lunchtime on Franck's car. That took a bit more time than we expected but nevertheless he completed the programme as planned which was good.

"Jarno also went through our programme and found some interesting bits in terms of the set-up. We will now have to analyse the work we have done this week and focus a little bit more on performance during the next test."

Toyota, however, faced a unique problem at the start of the day: the Japanese team ran out of fire extinguishers yesterday, having emptied all three on hand. Nevertheless, new ones were flown into the Middle Eastern track overnight.

Testing at Bahrain continues next week.

Today's times:

Pos  Driver       Team                    Time       Laps
 1.  Alonso       McLaren-Mercedes   (B)  1:30.994    73
 2.  Hamilton     McLaren-Mercedes   (B)  1:31.094    53
 3.  Massa        Ferrari            (B)  1:31.718    52
 4.  Raikkonen    Ferrari            (B)  1:31.867   100
 5.  Kovalainen   Renault            (B)  1:32.032    86
 6.  Barrichello  Honda              (B)  1:32.115   129
 7.  Button       Honda              (B)  1:32.137    78
 8.  Coulthard    Red Bull-Renault   (B)  1:32.220    73
 9.  Piquet       Renault            (B)  1:32.334   102
10.  Heidfeld     BMW Sauber         (B)  1:32.451    65
11.  Kubica       BMW Sauber         (B)  1:32.475    95
12.  Davidson     Super Aguri-Honda  (B)  1:32.553   126
13.  Montagny     Toyota             (B)  1:32.917   110
14.  Webber       Red Bull-Renault   (B)  1:33.034    73
15.  Trulli       Toyota             (B)  1:33.062   104
16.  Speed        Toro Rosso-Ferrari (B)  1:33.255    60

All timing unofficial