Q&A with Bridgestones Tetsuro Kobayashi 06 Mar 2009
During this weeks test at the Spanish circuit of Jerez, eight teams got the chance to evaluate Bridgestones tyres for 2009 and 2010, as well as a softer compound wet tyre designed for the Monaco Grand Prix, which was tested for possible use at other race venues. And so, despite the changeable weather conditions, it proved a busy time for the tyre manufacturers engineers. Technical manager Tetsuro Kobayashi reviews the five-day session...
Q: What was learnt from this test?
Tetsuro Kobayashi: Once more we have had a test which has been difficult for data collection with temperature changes and a lot of rain and high winds. With many different tyres used we have a lot to analyse, but we have seen no major issues. Teams understand that with so many regulation changes it will take time before they maximise their potential tyre performance, but we have definitely seen good progress.
Q: Why were so many different tyres tested in Jerez?
TK: Once the season has started we will not have testing like we have had in previous years so we have to make the most of pre and post-season testing. This is why we had many tyre specifications available in Jerez.
Q: Why is there such a difference using the wet tyres with the 2009 cars?
TK: The 2009 aerodynamic regulations have been designed to decrease the amount of downforce available. In the dry, the lost aerodynamic grip has been partially countered by the greater amount of grip from the slicks and the bigger contact patch they have with the track. In the wet, the aerodynamic situation is the same, but our tyre specifications have not changed since 2008, so this means there is less overall grip in the wet than previously, and the drivers have to adapt their driving accordingly.
Q: Can Bridgestone do anything to increase grip levels in the wet?
TK: Historically we have used a different wet compound for Monaco, where higher grip is required due to the smooth nature of this track. We have developed a new wet compound for Monaco in 2009, and we are currently evaluating if it is durable enough to take to other circuits to offer more grip.
Q: Can you explain the reasoning behind Bridgestone's recently announced tyre markings?
TK: We will mark the softer of the two compounds available at a race weekend with green bands on the outer edges of the sidewalls. We tested many different alternatives and this location gave the best visibility, from the side and also a head-on view. We have used the colour green as it shows our support of the FIA's Make Cars Green campaign.