315 is the tyre width in millimetres, 30 is the aspect ratio (sidewall height as a percentage of the width), R means radial construction, and 23 is the wheel diameter in inches. 315/30 R23 is therefore a very wide tyre with a short sidewall, typically chosen for 23-inch performance SUV wheels where steering response and grip are priorities.
315/30 R23 is most often fitted to high-performance SUVs and luxury SUVs with factory or approved 23-inch wheel packages. Common examples include the Lamborghini Urus, and select Range Rover variants specified with 23-inch rims. Always confirm the exact tyre size on your door placard or in the handbook before ordering.
Use the load index and speed rating shown on your current tyres or the vehicle placard, then match or exceed it when buying 315/30 R23. Many options in this size are Extra Load (XL) and high speed rated, which suits heavier, more powerful SUVs. Avoid fitting a lower load or speed rating than specified, as it can affect safety, insurance, and MOT compliance.
If your vehicle is specified for XL, you should buy 315/30 R23 in XL to carry the required weight at the correct pressures. This is common on performance SUVs that use this wide, low-profile size. If your vehicle is not specified for XL, stick to the manufacturer recommendation and keep the same specification across an axle.
Summer tyres in 315/30 R23 usually deliver the strongest dry and wet grip in warmer conditions, making them a popular match for performance SUVs. All-season tyres can be a better year-round option if you drive through colder weather and want more versatility without switching sets. When comparing options, prioritise the correct rating and choose the tread type that best fits your mileage, roads, and typical temperatures.