Bridgestone Potenza slick racing tyres made a return to Formula One cars for the first time in ten years as Bridgestone Motorsport completed its final test of the 2007 season after four days of running at Jerez.

Bridgestone Potenza slick prototype tyres were used alongside the 2007 specification medium compound dry grooved tyres by all eleven teams at the Spanish circuit. Teams used the 2008 specification ECU which means there was no traction control and a number of teams conducted runs with the slick development tyres simulating the 2009 regulations of lower downforce and no tyre blankets.

Three sets of slick tyres were available to all the teams to use over the course of the four days. Runs undertaken using these tyres did not count towards the 2007 testing agreement and valuable data was gained by the teams and Bridgestone.

Bridgestone Potenza Formula One tyres are scheduled to next be in use at a group test in 2008, where the medium compound dry grooved tyre will be in action at Jerez on January 14-16.

What has Bridgestone learnt from running with slick tyres at this test?
Hirohide Hamashima - Director of Bridgestone Motorsport Tyre Development: This test was a valuable data gathering exercise. We have to remember that these are development tyres and the 2007 chassis have not been designed to run with slicks. However, the information gained will help us and the teams with developments for the future. We received strong feedback from all drivers, including Michael Schumacher who we know well. It was good to see him here.

What is the plan for further tests and development of the slick tyres?
HH: We will review the information gained and this will enable us to continue to develop these tyres. The teams also now have initial information to help develop their cars. We will respond to requests from the Formula One Testing Committee for future tests as required and we would expect further tests over the course of next year.

How similar are these tyres to those used by Bridgestone in Formula One in 1997?
HH: We have learnt a lot since we last ran with slicks in F1 from our activities in Formula One and other motorsport activities like GP2, Champ Car and IndyCar, which all use our slick tyres. This knowledge has been incorporated into this development tyre and there are many differences from our 1997 tyres.

Have there been any major differences to tyre use and wear with no traction control?
HH: We have not seen a significant change to how the tyres are used when there is no traction control. Jerez is a circuit where traction control would be used more than Barcelona where we also saw cars running without it. Despite this, tyre performance has been good and in keeping with what we would see when traction control is employed.

How big a difference should we see in lap times from slick tyres?
HH: When the teams ran with 2007 levels of downforce certain cars were more than two seconds faster. When the cars ran with 2009 levels of downforce they were slower, which is the aim of the regulations. We must also remember that the current cars and their suspension have not been designed for slick tyres. A lot of development will occur in both the cars and the Bridgestone tyres before 2009.