Depending on the year and specification of your vehicle we would expect it to fitted with 16-inch wheels and 60 profile tyres, which should mean a relatively comfortable ride. You may wish to check the tyre pressures are set correctly as they may be overinflated. If you do need to change tyres we would suggest using a website such as blackcircles.com where you can view a selection of tyres to fit your vehicle. The Contact 2 is a reinforced tyre designed for heavier vehicles, so this may be the cause of the firm ride, so you may wish to switch to a non-XL rated tyre.