McLaren shows promise, but rain makes it a guessing game

Yet another weather-compromised Friday, with sporadic showers in the morning and full-on rain in the afternoon, made for an inconclusive picture at Hockenheim.

In particular it made assessment of the big McLaren upgrade difficult, for despite Jenson Button and Lewis Hamilton leading the overall times in the drier session, track conditions that were forever changing meant no direct comparison with Red Bull, Lotus, Mercedes etc. There may also have been less than met the eye in Hamilton being out on track together with Felipe Massa's Ferrari and lapping around 0.8s faster in the same conditions. Button's fastest time came in the early, dry, part of the session when most cars were still in the pits.

Initial signs for McLaren are promising, but with a qualification: the underlying difficulty the car has in switching on the intermediate tyre is still there and qualifying is forecast to be wet.

Sam Michael commented of the morning running: "We had probably the best session we could have in terms of a wet session. We still got through all the programme on the cars and now the engineers are busy going through the data to find out what's what. So far it looks positive."

Although the McLarens ran more laps than most, the weather still meant that it was not possible to back-to-back the new package with the old, as had originally been planned. All the running was on the new spec. The changes comprise totally new sidepods, changes to the diffuser, the exhaust exit and front and rear brake ducts. There are also mechanical changes that the team is reluctant to enlarge upon.

If this works as the simulation suggests, the team believe it will be worth more lap time than all the other upgrades this year combined. "I'm very optimistic about them," said Button. "They are very exciting if they work as hoped."

Lotus was encouraged by early data gathered by Kimi Raikkonen on its double DRS © XPB

But post-P2, Button confirmed the tyre temperature problem that could make the upgrade meaningless if it rains. "It's frustrating," he said. "The upgrades seem to be working. But we are still really struggling for tyre temperatures in the wet." Hamilton was slightly more upbeat. "The car is definitely better, but I just can't tell how much better yet. It's true it's quite tough in the wet but I think we'll be there or thereabouts."

There was just as much interest in Kimi Raikkonen's Lotus, which ran both sessions with the team's new 'double DRS' rear wing - understood to work in a different way to that on the Mercedes - and the team was delighted with what the loading sensors were telling them. The initial plan was that this wing would not be used for the race, but as things stood at the time of writing, its use had not been ruled out. Romain Grosjean ran the standard wing.

Ferrari's upgrades are more subtle, with a further modified front wing the most visible of them. Both Alonso and Massa were quick on dry, inters or wets and looked set to be a formidable threat come what may.

Red Bull didn't get any serious running in with the track at its driest and their places in the practices are totally unrepresentative. The track's combination of slow and medium speed corners would normally be expected to be perfect RB8 territory. Mark Webber, together with Jean-Eric Vergne and Charles Pic, tried the experimental new hard tyre. Everyone else stayed with the mediums that are the primes for this weekend and no-one got onto the softs.

Ostensibly, the layout of Hockenheim might be expected to suit Mercedes, with not too many fast, long-duration corners and both Nico Rosberg and Michael Schumacher were consistently quick when running. But a gearbox problem for Rosberg means he will drop five places. Damage to Schumacher's car after his late off in P2 was still being assessed at the time of writing.

Although Valtteri Bottas crashed the upgraded Williams in the morning, he had been by far the fastest man running in the patchily wet conditions and the car does seem to be well balanced and quick. Just how quick we cannot know.

Michael Schumacher severely crumpled his Mercedes W03 in P2 © LAT

The weather forecast - further rain on Saturday but a dry Sunday - gives an extra dimension to the challenge facing the teams, as a wet qualifying combined with a dry race brings a few key dilemmas, principally regarding wing levels and gear ratios.

Ignore the positions of the second session - as they simply reflected who was out on track at the most advantageous time when the track was at its driest and improving by big chunks each lap before heavy rain arrived again for the last 20 minutes. Like the similarly FP2-lowly Hamilton and Fernando Alonso, both Mercs were in the pits during that brief window.

Red Bull's Sebastian Vettel, Williams' Pastor Maldonado, Massa and Grosjean all took turns at heading the times during that window. The real picture will likely not emerge until the first pit stops on Sunday.