The challenge of completing a successful Friday programme at the Grand Prix weekend is often greater than it seems. Circuit conditions are typically difficult and dirty, so the drivers and engineers must work on choosing tyre types and making set-up changes even as the condition of the track is changing constantly.

Renault's Pat Symonds explains: "One often reads in the Friday press releases that teams have learnt much for the race and that not too much should be read into the lap-times. While these statements may seem evasive, it is a fact that the Friday sessions are the foundations of our race weekend, and only a disciplined approach pays dividends. This is especially true in Hungary."

The challenge for the engineering teams is of understanding how the changing conditions will affect the car's handling, and how much confidence can be placed in the results obtained on Friday. "At this track," explains Pat," we can reasonably expect the brake wear measured on Friday to double by the time we get to the race. Similarly, when it comes to the tyres, not only will the wear rate approximately halve by Sunday, but the way the tyres perform will change as the circuit cleans up and acquires a coating of rubber. We would expect any graining on Friday to disappear by the race, and in contrast the rear tyre temperatures will significantly increase as grip levels rise. This means that an under-steering, front-limited car on Friday will transition to a well-balanced, or even over-steering, race car by Sunday."

The Hungaroring, though, still reserves some surprises. Today has seen strong winds blowing, meaning that circuit conditions can not even be relied upon to evolve in a predictable manner. "The way the circuit cleans up here in Hungary is very dependent on the prevailing winds," concludes Pat. "Last year, conditions evolved very little during the weekend, and the times set in the Heathrow test session were not bettered until qualifying. This year, the organisers removed four tonnes of sand from the track before practice, but it is likely that the winds we have seen today will be re-depositing this back on the circuit all the time."