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

You answered correctly. Using winter tyres in summer increases both fuel consumption and tyre wear. This is because winter tyres are made of a softer rubber compound that wears out faster in warm temperatures and creates more rolling resistance, causing your car to use more fuel. Driving stability, however, is not necessarily improved; in fact, winter tyres in summer often have less grip and can actually reduce safety. So, the correct answers are increased fuel consumption and increased tyre wear. Remember, it’s best to switch to summer tyres as soon as temperatures stay above 7°C.