Williams technical director Sam Michael has praised Nico Rosberg's fourth place in the German Grand Prix on Sunday, after the youngster came through the field after a disappointing qualifying effort to record his highest finish of the 2009 F1 season.
The Grove-based team maintained a high level of car development in the break between Silverstone and the Nurburgring, and brought a detailed aero upgrade to the German round, comprising a new front wing as well as diffuser and engine cover modifications. The upgrade was validated during Friday's practice sessions and remained on the car for the remainder of the weekend, but a change in direction on Friday and Saturday morning, intended to help the team prepare for Q3, meant that it didn't expect to run at the top of the timesheets in practice, as had been the case earlier in the season, when Rosberg frequently snatched top spot in practice.
"We're improving the performance levels of the FW31 every race," Michael commented, "and that's translating into greater competitiveness across a variety of tracks. All the teams are bringing upgrades to each race, so it's encouraging to see that our development plan is working."
Both Friday and Saturday running was dominated by gusty wind conditions and low track temperatures, making tyre warm-up difficult and, although both Rosberg and team-mate Kazuki Nakajima progressed cleanly through the first phase of qualifying, struggled to progress to the top ten shoot-out as they had at Silverstone.
Starting Q2 on option tyres, the team adopted a similar programme to many of its competitors and quickly aborted its first run on both cars as the rain fell, pitting for intermediates instead. Finding sufficient pace on the new rubber proved problematic for both drivers, a situation that wasn't improved when there was a brief window for slicks which Rosberg managed to take advantage of, but still found himself unable to repeat the good pace he had found in Q1.
As a consequence, the qualifying performance was disappointing and the team took the decision to fuel the cars for a long first stint and start Sunday's race on prime tyres, required given the penalty of carrying additional fuel.
"It was difficult to get the tyres up to their correct operating conditions and then to keep them there," Michael confirmed, "Like the rest of the field, we did one lap on slick tyres, but abandoned it when it started to rain and switched to intermediates.
"While on the inters, Kazuki radioed in to say that the track was ready to go back on slicks, but it would be prudent to do another lap on the Inters. That almost paid off for him but, by the time he went back out on the slicks, it had rained again and we'd missed the window. Nico was on a similar strategy - he was out on track at the right time with the slicks, but his car balance wasn't right.
"It was clear as early as Friday morning that it was going to be an issue and remain so throughout the weekend. When that happens, there is also a high risk of graining, which is why we opted to run the harder prime tyre for the majority of the race. There was some luck going on with the choices we made, but it was the same for everyone and we just didn't do as good a job as the other teams."