The German, who completed 78 laps in the Mercedes-powered VJM07, edged out Ferrari’s Fernando Alonso and Mercedes’ Lewis Hamilton with a lap time that was some 0.081s quicker than last year’s fastest race lap in Sakhir.
“A very positive and satisfying day,” commented Hulkenberg. “We had a busy programme and we learned a lot. Time in the car is very valuable at the moment and so it feels good to cover so many laps and even complete two long runs at the end of the day. That gave me a chance to see how the car behaves and to start getting a feel for it, which was not something I was able to do in Jerez.
“It’s great that we’ve already done some set-up work and started to improve the drivability of the car. But it’s still very early stages; we are learning with every lap and we face a very steep learning curve in the coming days. ”
Alonso’s Ferrari, which had earlier brought out the red flags after an oil leak, was the only non-Mercedes-powered car in the top four, with Hamilton and McLaren rookie Kevin Magnussen both taking turns to top the times before settling for third and fourth places respectively, behind the Spaniard.
“Today was another good test of the car to see if any issues came up - we had a small issue with the brakes at the end but were still able to achieve a lot of laps today,” said Hamilton.
“We're not aiming to be top of the timesheets at the moment, it's more about ticking the reliability boxes, but we can be happy with where we are before the halfway point of the pre-season tests.”
Alonso, Hamilton and Magnussen all completed more than 60 laps, confirming the promising reliability of their new cars.
“It’s nice to be driving again, especially when you have more reference points compared to the previous time, which means you get a better feeling for the car,” said Alonso, who spent much of the day working on the new brake-by-wire system on his F14 T.
“We are also at a track that is more representative, with normal temperatures, where it’s been easier to understand tyre behaviour. We are in a phase where we are discovering things and with every lap, we learn something new. For everyone, there is still a lot to do to be well prepared for Melbourne, so it will be important to make the most of every day we have available to us.”
The fifth fastest time of the day went to Red Bull’s Sebastian Vettel, but it was in truth another disappointing session for the world champions who arrived in Bahrain having completed just 21 laps in four days at the first test in Spain owing to technical problems. On Wednesday the Milton Keynes-based squad managed to reach two thirds of that total - 14 - but the Renault-powered RB10 didn’t actually make it out of the garage until the afternoon, and it wasn’t long before Vettel was parking it at the side of the track and bringing out the red flags once more.
“It’s been a very long two weeks for everyone back at the factory and I have to say that while it might not appear so on the surface there has been a big improvement since Jerez,” said Red Bull’s race engineering co-ordinator, Andy Damerum.
“We are obviously playing catch-up and for us this was very much like a first test, so we were sending the car out to do one lap, then two and trying to build from there. In that regard the laps completed were good.
"However, we were sidelined by a mechanical gremlin but one unrelated to the issues in Jerez. That’s the way of testing. All these problems have to be ironed out and only reveal themselves as you progress. We’ll look at solving that issue now and we’re itching to get out on track again tomorrow.”
Adrian Sutil, a spinner at Turn 1 in the morning, posted the sixth best time, but perhaps more tellingly his Sauber completed the most laps of any car - 82. Caterham tester Robin Frijns was seventh fastest, whilst Russian rookie Daniil Kvyat had a frustrating day in the Renault-powered Toro Rosso as technical problems restricted him to just five laps.
The final driver to post a time was Romain Grosjean who gave the radical split-nosed Lotus E22 its official debut. Having missed the Jerez test, the Enstone-based team were looking to make up for lost time, but technical issues meant that Grosjean was able to complete just 8 laps and spent the majority of the day confined to the garage.
“Obviously that wasn’t the day we wanted to have and there are few conclusions we can draw so far as our running was so limited,” explained Lotus’s trackside operations director, Alan Permane.
“It’s no secret that we’re frustrated as we want to get laps on the board to understand our new car and all the different elements it contains. The power units contain a lot of new technology and certainly we had issues with the energy store unit today. We changed this unit during the course of the day, which is not the work of a moment. Certainly we hope for a better day tomorrow.”
Felipe Massa and Jules Bianchi also made appearances on track, for Williams and Marussia respectively, but both had their running severely restricted by technical problems. Williams reported a fuel system issue on the Mercedes-powered FW36, whilst Marussia suffered an IT configuration problem.
Testing continues in Bahrain on Thursday.
Unofficial Wednesday test times from Bahrain:
1. Nico Hulkenberg, Force India, 1m36.880s, 78 laps
2. Fernando Alonso, Ferrari, 1m37.879s, 64 laps
3. Lewis Hamilton, Mercedes, 1m37.908s, 74 laps
4. Kevin Magnussen, McLaren, 1m38.295s, 81 laps
5. Sebastian Vettel, Red Bull, 1m40.224s, 14 laps
6. Adrian Sutil, Sauber, 1m40.443s, 82 laps
7. Robin Frijns, Caterham, 1m42.534s, 68 laps
8. Daniil Kvyat, Toro Rosso, 1m44.346s, 5 laps
9. Romain Grosjean, Lotus, 1m44.832s, 8 laps
10. Felipe Massa, Williams, no time, 5 laps
11. Jules Bianchi, Marussia, no time, 3 laps