255 is the tyre width in millimetres, 70 is the sidewall height as a percentage of the width, R means radial construction, and 15 is the wheel diameter in inches. Confirm the size by checking the tyre sidewall, then match it to your vehicle handbook or the tyre placard (often in the door shut or fuel flap). Also verify the load index and speed rating, as the correct 255/70 R15 size still needs the right rating for your vehicle.
They are very close in overall diameter and width, so they are often treated as near equivalents for 15-inch 4x4 fitments. However, exact measurements vary by brand and tread type, and a small difference can affect steering clearance and speedometer reading. If your vehicle specifies 255/70 R15, it is best to stick with it unless you have checked clearance and insurance requirements.
In most cases, moving to 255/70 R15 gives a slightly narrower tyre and a slightly smaller overall diameter than 265/70 R15. That can help with arch and suspension clearance, but it may also alter gearing and speedometer accuracy. Keep tyre sizes matched across an axle, and do not choose a lower load index or speed rating than your current specification.
Start with the load index shown on your current tyres or vehicle placard and choose the same or higher. Pickups that carry tools, tow, or run off-road may need a higher load rating or a more robust construction, depending on the original fitment. If you are unsure, share your current tyre markings and vehicle details, then select 255/70 R15 options that meet or exceed that rating.
For mostly tarmac driving, road tyres in 255/70 R15 prioritise low noise, wet grip and stable handling. If you regularly drive on gravel, fields or tracks, an all-terrain pattern balances on-road manners with stronger traction and tougher shoulders. Mud-terrain tyres suit deep mud and ruts, but they are typically louder and can feel less settled on wet roads, so they are best chosen when off-road use is the priority.
