The 2010 GP2 Series calendar now comprises 10 venues, two of these providing a heat durability test for Bridgestone's Potenza slicks.

Each of Bridgestone's GP2 dry tyre compounds has a specific working range, this being the range of temperatures within which they operate to their maximum performance.

In GP2 historically the hottest race weekends on the calendar have been Valencia and Istanbul. In 2009 at Valencia (GP2 is running there two months earlier this year, in June) the track temperature reached 47ºC during the races, with ambient temperatures hitting up to 32ºC.

By comparison, Istanbul provided temperature readings of 45ºC track and 30ºC ambient last year (43ºC track and 28ºC last month, as part of the current GP2 season).

Valencia does not provide the same high sustained load on the tyres that is experienced at Istanbul, meaning Bridgestone can provide a soft tyre in Valencia which gives higher grip and traction (with optimum performance being achieved within a high working range). However, in Turkey, the medium compound dry tyre is used (instead of the soft specification) to withstand the amount of stress that is inflicted on the front rights due to the severe track characteristics.

In hot temperatures tyres can show higher levels of degradation and wear, all of which if not accounted for by the drivers and teams could affect race performance and results.

It is up to the drivers to be aware of the tyres' operating windows and to understand how to preserve and maintain them in varying conditions.

Chris Tandy - Bridgestone Motorsport Senior Engineer: "The importance of track temperature is a major factor that the teams must understand. Track temperature dictates tyre running temperature. If the GP2 teams anticipate the correct range of running temperature based on track measurements they will be far closer to idealised running pressures. This will equate to consistency on-track and a good car balance, leading to steady and quick lap times."