Massa masters the wet as McLaren and Red Bull row over diffuser ban

Fans are left to shiver in the rain while Horner and Whitmarsh get hot over rule change

What effect has the ban on off-throttle blown diffusers had here?

Have Red Bull been neutered? Are McLaren and Ferrari going to have a better chance against the cars from Milton Keynes – or is the British Grand Prix going to be just another "Vetfest", as world champion Sebastian Vettel runs away and hides on a track that historically suits Adrian Newey's downforce-laden machines, which won here in 2009 and last year?

Your guess is as good as any. Thanks to the vagaries of the British weather, which steadfastly refused to take any sympathetic account of the heroic efforts that the British Racing Drivers' Club and Silverstone Circuits have made not just to safeguard the long-term future of the race but to deliver the dramatic new £28m "Wing" pits and paddock complex a year ahead of schedule, both practice sessions were literally washouts yesterday.

Last year's victor Mark Webber set the fastest time in the first session, held over 90 minutes in the morning, more than half a second clear of Michael Schumacher's Mercedes. In the afternoon they were again the pacesetters until conditions improved so quickly in the final 10 minutes that they found themselves down in 14th and 12th positions respectively, as Felipe Massa forged through for Ferrari, ahead of Nico Rosberg's Mercedes.

Lewis Hamilton ventured out on Pirelli's slick tyres for a while in the morning, but soon abandoned that adventure and switched, like everyone else, to the Italian company's intermediate pattern wet-weather tyres. Such was the unexpected unpleasantness of the weather that an extra supply of 24 sets of the tyres had to be trucked in.

"The weather meant it was a difficult day, with rain affecting both the first and second sessions," Massa said. "However, it seems to me that the car handles pretty well in the wet, which is positive in terms of the rest of the weekend, given that there's a strong chance of more rain.

"That is also the reason why I only used one set of intermediate tyres: I had a bit of graining on the fronts, especially at the start of the second session, but towards the end the situation improved and the performance of the tyre got better all the time.

"It's pretty difficult to say where we are compared to the others," Massa added, "however, as the track conditions were changing continuously and it's not even easy to give an in-depth evaluation of the new components we brought here."

Christian Horner, the Red Bull team principal, summed things up perfectly when he said: "In reality, we learned very little today. It's been a particularly English summer's day – almost with three seasons in one day. We ran on Pirelli's inters, learned a bit about the pit lane, sorted out our the new garage... It's been a restrictive day in terms of what we managed to learn on track, to be honest."

The matter has been further complicated as some teams have been allowed different percentages of exhaust blowing on the overrun after lobbying the FIA. Renault, who supply Red Bull's engines, are believed to have successfully argued a percentage that has upset others, such as Mercedes, and led to a lively debate between Horner and McLaren's Martin Whitmarsh, whose team use the German engines, about the semantics of allowing engines to fire on the overrun and thus maintain a degree of the downforce generation that the rule change was intended to ban.

"There are secondary benefits," Horner conceded of the percentage that Renault have been allowed, said by some to be 50 per cent. "But it is an extraordinarily complex matter, and there are issues of control and reliability to be taken into account, too, because in some cases it's a necessary part of the engine's operation.

"It's very difficult for the FIA to pick their way through this, but they have been as fair as they agreed to be. We aren't completely happy, and I'm sure McLaren aren't, but it's all circumstantial."

Whitmarsh, for his part, said: "There have been about six directives from the FIA, but when the goalposts were being moved halfway through practice it makes things very complicated. In hindsight it would be better to make these changes at the end of the season, because in a competitive environment every team is going to feel hard done by."

A much-needed moment of levity was introduced when a listening Tony Fernandes, the owner of Team Lotus, interjected: "I think it's a little bit of a shambles to have these kind of discussions now. The rules should be very clear so we don't have these 10 per cent blowing, 50 per cent blowing arguments. Some of the greyness should be taken out.

"The rules should be changed at the end of a year. You don't get this in football, where everyone can understand the rules. I didn't understand a word of what either of you were just saying!"

If anyone had the right to feel hard done by yesterday, however, it was the bedraggled fans in the grandstands, who had a gruelling day. Doubtless all many of them cared about blown exhausts was that having one themselves might have kept them from freezing in the inhospitable conditions.

In the morning, Sauber driver Kamui Kobayashi put their hearts momentarily into their mouths when he spun exiting Club corner, which under the new layout now marks the end of the 5.8 km lap. The Japanese driver wrestled for control before the car finally got away from him, and was lucky not to overturn as it bounced over a kerb before clattering into the wall and damaging its right-hand suspension. However, in the afternoon there was nothing to watch for the first 45 minutes after Spaniard Jaime Alguersuari fell foul of the standing water there and spun without damage, discouraging his fellow drivers from venturing out.

The forecast currently suggests that today's final practice session should be dry, before the rain returns for qualifying. Even some respite from the weather would be a relief.

Silverstone Practice

First Practice: 1 M Webber (Aus) Red Bull-Renault 1min 46.603secs; 2 M Schumacher (Ger) Mercedes GP 1:47.263; 3 R Barrichello (Br) Williams-Cosworth 1:47.347; 4 S Perez (Mex) Sauber 1:47.422; 5 F Massa (Br) Ferrari 1:47.562; 6 N Rosberg (Ger) Mercedes GP 1:47.758; 7 F Alonso (Sp) Ferrari 1:48.161; 8 L Hamilton (GB) McLaren-Mercedes 1:48.549; 9 N Hulkenberg (Ger) Force India-Mercedes 1:48.598; 10 J Alguersuari (Sp) Toro Rosso-Ferrari 1:48.678; 11 P Di Resta (GB) Force India-Mercedes 1:48.730; 12 S Buemi (Swit) Toro Rosso-Ferrari 1:48.778; 13 S Vettel (Ger) Red Bull-Renault 1:48.794; 14 P Maldonado (Ven) Williams-Cosworth 1:48.809; 15 J Button (GB) McLaren-Mercedes 1:48.841; 16 N Heidfeld (Ger) Renault 1:48.941; 17 V Petrov (Rus) Renault 1:49.603; 18 K Kobayashi (Japan) Sauber 1:50.133; 19 J Trulli (It) Lotus-Renault 1:50.222; 20 K Chandhok (India) Lotus-Renault 1:51.119; 21 T Glock (Ger) Virgin-Cosworth 1:52.470; 22 V Liuzzi (It) Hispania-Cosworth 1:53.143; 23 J d'Ambrosio (Bel) Virgin-Cosworth 1:53.469; 24 D Ricciardo (Aus) Hispania-Cosworth 1:54.334. Second Practice: 1 F Massa 1min 49.967secs; 2 N Rosberg 1:50.744; 3 K Kobayashi 1:51.395; 4 L Hamilton 1:51.438; 5 J Button 1:51.518; 6 A Sutil (Ger) Force India-Mercedes 1:51.738; 7 P Di Resta 1:51.781; 8 R Barrichello 1:51.992; 9 S Perez 1:52.169; 10 S Buemi 1:52.189; 11 V Petrov 1:52.198; 12 M Schumacher 1:52.325; 13 H Kovalainen (Fin) Lotus-Renault 1:52.578; 14 M Webber 1:52.587; 15 F Alonso 1:52.869; 16 N Heidfeld 1:54.023; 17 J Alguersuari 1:54.274; 18 S Vettel 1:54.545; 19 J d'Ambrosio 1:54.714; 20 P Maldonado 1:55.155; 21 J Trulli 1:55.155; 22 T Glock 1:55.549; 23 D Ricciardo 1:55.828; 24 V Liuzzi 1:56.037.

Drivers' Standings

1. S Vettel (Ger) Red Bull-Renault 186pts

2. J Button (GB) McLaren-Mercedes 109

3. M Webber (Aus) Red Bull-Renault 109

4. L Hamilton (GB) McLaren-Mercedes 97

5. F Alonso (Sp) Ferrari 87

6. F Massa (Br) Ferrari 42

7. N Rosberg (Ger) Mercedes GP 32

8. V Petrov (Rus) Renault 31

9. N Heidfeld (Ger) Renault 30

10. M Schumacher (Ger) Mercedes GP 26

11. K Kobayashi (Japan) Sauber-Ferrari 25

12. A Sutil (Ger) Force India 10

13. J Alguersuari (Sp) Toro Rosso-Ferrari 8

14. S Buemi (Swit) Toro Rosso-Ferrari 8

15. R Barrichello (Br) Williams-Cosworth 4

16. S Perez (Mex) Sauber-Ferrari 2

17. P di Resta (GB) Force India-Mercedes 2

Constructors' Standings

1. Red Bull-Renault 295pts

2. McLaren-Mercedes 206

3. Ferrari 129

4. Renault 61

5. Mercedes GP 58

6. Sauber 27

7. Toro Rosso-Ferrari 16

8. Force India-Mercedes 12

9. Williams-Cosworth 4