Match the size printed on your current tyre sidewall with the vehicle placard (usually in the driver door shut) and the owner’s handbook. Some 4x4s run different sizes front and rear, so check all four positions before ordering. If the placard lists more than one approved size, choose the 285/55 R18 option only if it is explicitly shown.

Use the load index and speed rating specified by the vehicle manufacturer on the placard or in the handbook. For 285/55 R18, higher load ratings are common because the size is often fitted to heavier vehicles, especially when towing or carrying loads. You can usually go higher than the required rating, but do not go below it, and keep tyres matched across each axle.

Pick road-focused tyres if most miles are on motorways and A-roads and you want lower noise and better wet braking. All-terrain tyres suit mixed use such as gravel tracks, fields and winter lanes while still behaving predictably on tarmac. Mud terrain options are best for regular deep mud and ruts, but they are typically louder and can increase rolling resistance on-road.

A taller size increases overall diameter and can affect speedometer accuracy, gearing, ABS calibration and wheel-arch clearance. Moving from 285/55 R18 to 285/60 R18 changes diameter by roughly 3.7%, which is often outside common fitment tolerances. Check the vehicle’s approved tyre sizes first and, if unsure, confirm with a tyre specialist before buying.

Follow the pressure values on your vehicle’s tyre placard, as they are set for the vehicle’s weight, suspension and intended load. Pressures can differ for normal driving, heavy loads and towing, so use the correct setting for how you drive. Check pressures when tyres are cold and re-check regularly, especially in colder weather.