Mat Coch writes:

Today’s changeable weather proved to be not only a challenge for the drivers but also Pirelli, which had its new hard compound testing all but ruined by the onset of rain.

The Italian firm debuted a development compound hard tyre during Friday practice at Silverstone and had hoped to gain further data on the rubber this weekend. The weather however had different ideas, teams only getting a handful of laps in dry conditions.

Pirelli had hoped to use the tyres to gain a better understanding of the way a 2012-spec car heats and wears its tyres against Pirelli’s test car, a 2010-spec Renault. “We had a few laps but learned absolutely nothing, basically,” Paul Hembery laughed.

“It's been hard to correlate what we've seen on our own test car with what we're seeing on the track,” he continued. “We don't see the temperature deltas between front and rear that we see on some cars here. We haven't seen the sensitivities that some of the cars have had.”

With no meaningful running on the tyres Hembery is now looking at possible alternatives later in the season. “In Hungary they'd be useless,” he explained. “If it had been nice and warm here it would have allowed us to do a bit of scaling work but we don't think in Hungary they'd actually be of any use to us.

“It's not really much point in Monza and we haven't got the time for Spa,” he continued. “We'll have to think about doing something later in the season. Ideally I'd like to take it to Suzuka, have a go there.”

While the wet weather ruined Pirelli’s plans with its new hard tyre the day wasn’t completely wasted. “It's probably useful from running in the second session with the intermediate tyre because we had the track which was drying out rapidly,” Hembery explained.

“As the track dried we saw that the intermediate tyre was holding up well, some 15/16 laps running out of it and it probably would have gone longer if the rain hadn't come back. We were getting close to the cross over point for getting to dry running; a couple more laps and we could have been there.”

It’s the Italian firm’s first visit to Hockenheim, meaning neither it nor the teams have any concrete idea of how the tyres are likely to wear. Wet running on Friday is expected to carry on in to Saturday, while the race itself looks set to be run in dry conditions. It leaves teams without the data they usually enjoy when determining their car setup and strategy.

Hembery however is convinced they’ll cope. “They will have pretty good ideas on what they need in terms of some good wear data,” he claimed. “They all have their own simulation data coming in to the race. They'll all have been driving around in their simulators at home estimating, so they will have pretty good ideas.”

A two-stop race is expected on Sunday should conditions be dry, though if the weather cools down it may encourage some to opt for a single stop.

Check out our Friday gallery, here.