Key is to monitor the tread depth of the tyres. Low tread depth decreases the key properties of the tyres such as grip, control and the ability to avoid aquaplaning. You need to have tyres with a tread depth of over 4 mm to be safe when driving. Make sure to rotate the position of your tyres between each tyre change, so that they will wear out evenly. This is even more important if you have a hybrid or an electrical car, as the tyre wear is higher with these due to the higher weight caused by the battery packs. You always want to purchase 4 new tyres and not less, as you want to make sure that all tyres have the same grip on all positions around the car. For more information regarding good quality tyres, visit: https://brightonparkblog.com/2020/06/16/safe-tyres-for-safe-driving/