In Formula 1 racing, the prime tyre is the harder of the two tyre compounds available to the teams during a race weekend.
Because prime tyres have a softer, grippier compound they generally last longer than option tyres, but do not produce lap times which are as fast. However, the effect varies with the track layout and temperature.
During a dry-weather race, drivers are required to use both prime and option tyres. The rule does not apply in wet-weather races, when wet tyres are used.
See also option tyre
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