Ferrari’s Sebastian Vettel topped the timesheet in a rain-affected final practice session in Austria. McLaren, already hampered by engine-related grid penalties, hit more trouble as Fernando Alonso stopped on the start/finish straight with a gearbox problem.

The session began in overcast conditions but as normal drivers began the hour-long session with runs on the prime tyres, soft in this case, in the expectation of getting in a qualifying simulation on the quicker option supersoft tyres at the end of the session.

It was during this opening phase that Vettel claimed top spot, lapping in 1:09.994 on soft tyres to shade Mercedes’ Lewis Hamilton by just 0.017s. Third place went to Kimi Räikkinen in the second Ferrari.

The Finn finished four hundredths of a second ahead of Force India’s Sergio Pérez the only driver in the top five to set his time on the supersoft tyres. Nico Rosberg was fifth for Mercedes with a time of 1:10.332, three tenths adrift of Vettel’s time.

Halfway through the session the leading drivers attempted to beat the oncoming rain by bolting on supersoft tyres but their efforts were thwarted when Alonso’s McLaren ground to a halt on the pit straight.

With the car positioned as it was the red flags came out to stop the session, just as the leaders began to take on the option tyre in anticipation of a swift restart and a chance to put in a qualifying run. The chance never came, however, as within moments rain began to fall across the Red Bull Ring.

It quickly intensified and when the pit lane opened again Rosberg was swiftly told that he’d need to box again straight away. Like his front-running rivals the German tip-toed around the circuit but slithered off track at Turn 2. Räikkonen, too, had his own off at Turn 6 and at the end of the lap the drivers crawled back to the pit lane to wait it out.

With 20 minutes to go Force India’s Nico Hulkenberg tested the conditions on intermediate tyres but reported that there was “no grip at all”. That was confirmed moments later when Toro Rosso’s Carlos Sainz had a spin at Turn 3. Vettel too ventured out but spun at Turn 2 and then Raikkonen lost control at Turn 3. Rosberg then returned to the fray on full wet tyres but the chequered flag was soon out and the disrupted session came to an end.

At McLaren, Alonso’s stop heaped more woe on the struggling team. Already hit with a 25-place grid penalty for Jenson Button and a 20-place penalty for Alonso because of changes to the Honda power units in the drivers’ cars, the team faced more work as they effected another gearbox change on the Spaniard’s car.

As neither driver serve the full grid drop tomorrow they will likely be handed time penalties during the race.

Elsewhere, Red Bull Racing's Daniil Kvyat will take a 10-place grid drop as the team was forced to fit a fifth engine to his car.

2015 Ausrtrian Grand Prix – Free Practice 3
1 Sebastian Vettel Ferrari 1:09.994 16
2 Lewis Hamilton Mercedes 1:10.011 0.017 16
3 Kimi Raikkonen Ferrari 1:10.177 0.183 12
4 Sergio Perez Force India 1:10.221 0.227 14
5 Nico Rosberg Mercedes 1:10.332 0.338 23
6 Felipe Massa Williams 1:10.408 0.414 18
7 Valtteri Bottas Williams 1:10.417 0.423 14
8 Max Verstappen Toro Rosso 1:10.436 0.442 23
9 Pastor Maldonado Lotus 1:10.576 0.582 12
10 Romain Grosjean Lotus 1:10.863 0.869 8
11 Nico Hulkenberg Force India 1:11.009 1.015 14
12 Marcus Ericsson Sauber 1:11.058 1.064 22
13 Carlos Sainz Toro Rosso 1:11.139 1.145 18
14 Daniil Kvyat Red Bull Racing 1:11.139 1.145 14
15 Fernando Alonso McLaren 1:11.168 1.174 13
16 Daniel Ricciardo Red Bull Racing 1:11.819 1.825 10
17 Felipe Nasr Sauber 1:11.906 1.912 9
18 Jenson Button McLaren 1:12.616 2.622 16
19 Will Stevens Manor 1:13.328 3.334 14
20 Roberto Merhi Manor 1:13.960 3.966 8

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