Q. Can you clarify how many specifications of tire Bridgestone will be producing this year
Kees van de Grint, Bridgestone Motorsport Head of Track Engineering Operations: The current plan is to produce four specifications of dry weather tire which will be known as: Hard, Medium, Soft and Super Soft. From these four specifications two will be chosen for use at each Grand Prix.
Q. What were the aims of this week's test and which tires were tested at Valencia?
KvdG: This week's test was the only opportunity for the teams and drivers to conduct comparisons of the medium and soft Bridgestone specifications prior to their use at the Australian Grand Prix in March. It was also a good opportunity to ascertain what the potential lap time difference may be between those two specifications.
Q. Did all the drivers manage to complete comparisons between the soft and medium tires?
KvdG: The majority of drivers this week did run on both specifications, giving them a feel for what to expect in Melbourne.
Q. And what was the feedback?
KvdG: We were pleased to see that the soft tire performed as it should in comparison to the medium specification, providing more grip and a faster lap time.
As you would expect from a softer tire, there was also a little more graining and a higher rate of degradation on Thursday than with the medium specification but those drivers who ran today (Friday) will have found that the drop off improved over the day as track conditions also improved.
Just as importantly, however, it was good to see that the medium specification was providing a very consistent level of performance for the drivers.
Q. What was the time difference between the medium and soft specifications?
KvdG: First impressions suggest an average lap time difference of half a second between the medium and faster soft specification.
Q. How are the teams adapting to the new tires?
KvdG: The teams have been adapting very well and it is clear that they have moved on significantly since November in terms of their knowledge and use of the tires.
They have become more confident and their understanding of the Bridgestone tires has evolved enough for them to be concentrating more on fine tuning their cars to the tires, not having to make big changes.
From studying the lap times I think it is going to be very close this year. And now that many of the teams have launched their 2007 cars it has been interesting to see the differences in design approaches between them.
Q. How is Bridgestone handling the practical side of supplying all the teams this year?
KvdG: It's a challenge we are enjoying and we have employed additional staff to fulfill the servicing requirements of all eleven teams this year. Bridgestone's technical department in Japan has also seconded extra engineering staff to our F1 facility in the UK.