Bridgestone to use green markings

The different tyres were previously denoted by a white line in the rubber's grooves, but the return of slicks for 2009 makes this impossible, so the green markings will be used instead.

The Japanese company has also revealed that there will be a more distinct difference between the two compounds used at each race this year.

Until now the two types of tyre were consecutive in Bridgestone's range - for instance super soft and soft - whereas this season at most races the two tyre compounds will be further apart in performance and characteristics. For example in Melbourne all drivers must run both super softs and medium Bridgestones during the race, while at Sepang both soft and hard tyres will be mandated.

Bridgestone's director of motorsport tyre development Hirohide Hamashima believes the changes will make the racing more exciting.

"From our perspective we have changed our allocation strategy so that we can bring non-consecutive allocations to races," he said.

"The compounds will not only vary in terms of compound hardness, but also working range. We have tried to have one tyre which has a quick warm-up and delivers a fast lap time immediately, and the other tyre which has a higher working range, so will not deliver immediate fast times, but gives very consistent and durable performance when it is at its operating temperature.

"Of course, we are subject to many variables such as different cars and drivers, not to mention the weather, which was such a big factor in 2008.

"We hope that the change in allocations gives competitors a good challenge and the fans entertaining racing."