Exclusively KUMHO ECSTA, limited to 60 sets of tyres per season per team. Three sets of tyres per weekend per team. Two sets of wet-weather tyres per race weekend, but their use is allowed in the case of a 'Wet Race' only. Tyres to be filled with environmental air or nitrogen; chemical or mechanical treatment is prohibited. Tyre dimensions: 180/550 R 13 front, 240/570 R 13 rear. Tyre heaters are not allowed.