My tread is fine but the tyres are years old. Do they still need changing?

Possibly. Tread depth is only half the story, and on low mileage cars, second cars and vehicles that sit on a drive through the winter it is age that gets them first. Rubber hardens and the sidewalls start to craze, so grip in the wet drops well before the tread runs out. Find the four digit code on the sidewall, so 3221 means week 32 of 2021. Anything past five years is worth a proper look and anything near ten should be replaced whatever the tread says. Bring it in for a tyre safety check and we will give you an honest answer.