Changing the size of the tyre fitted to the car can improve vehicle roadholding and other handling aspects. Most frequently the new tyres that are selected have an increased section width (they are wider) and a lower aspect ratio or profile (they have a lower sidewall height).

But there's a few things that you have to know about when swapping-in bigger tyres. Firstly, increasing just the width of the tyre while retaining the same profile will cause an increase in the diameter of the...