What is caused by driving with winter tyres during the summer months?

You answered correctly. Driving with winter tyres in summer causes increased fuel consumption and faster tyre wear. Winter tyres have a softer rubber compound designed for cold temperatures, which wears out more quickly on warm roads. Additionally, the higher rolling resistance of winter tyres leads to greater fuel consumption in summer conditions. However, winter tyres do not increase driving stability in summer; in fact, they may reduce it compared to summer tyres. Remember to switch to summer tyres when the temperature stays consistently above 7°C to ensure optimal safety and efficiency.