“Underinflated tyres and extreme temperatures on long journeys can be dangerous,” warns Andreas Schlenke of Continental’s tyre development division in Hanover. “Contact with the hot asphalt and the high air temperatures prevent a tyre from cooling down. If the tyre is underinflated, tyre shoulder and sidewall deformation can occur, resulting in rolling resistance. This causes the rubber to heat up even more. If all these factors combine, or if the tyre has been previously damaged by curb contact or the like, a blowout is a distinct possibility.”
Even at an air temperature of 30 degrees, the asphalt can heat up to 60 degrees. The heat wave in Europe is already pushing temperatures up to 40 degrees in some places, and the forecast for southern Europe is already close to 50 degrees. “Asphalt temperatures of over 80 degrees Celsius are entirely possible,” explains Schlenke. “You shouldn’t endanger your safety with unnecessary car trips in temperatures like this,” he advises. Driving on winter tyres in these conditions is extremely risky because their rubber compound is softer than summer tyres and heats up more. “This can be really dangerous,” he warns. “Drivers who think they can save money driving on winter tyres in high temperatures are endangering themselves and others because a tyreire blowout at high speeds is always dangerous.” Even in high temperatures, cars running on all-season tyres are safe to drive if they’re correctly inflated – their tread and rubber are a mix between summer and winter tyres, so they’re not as sensitive to heat as winter tyres.
Continental advises all drivers to drink plenty of fluids and stay in the shade or indoors as much as possible during periods of high temperatures – and not to park where the car and its tyres are exposed to direct sunlight.