265/65R17 vs 265/70R17 - Can You Swap Them? [Metric/Inches]

Are you considering swapping your vehicle’s tyres but unsure about the differences between 265/65R17 and 265/70R17 sizes?

Knowing their differences may help you evaluate how the changes may affect your vehicle’s ground clearance, ride comfort, speedometer accuracy, and overall performance.

Need guidance on what to remember when switching tyre sizes? Let us help you out!

Diameter

Tyre diameter refers to the measurement from one end of the tyre to the other through its centre.

The 265/65R17 size has an approximate diameter of 776.3mm or 30.6 inches, while the 265/70R17 tyre size has a diameter of around 802.8mm or 31.6 inches.

As the difference is less than 50mm, you can legally swap the 265/65R17 size for the 265/70R17 size if you have a 4WD vehicle, according to the VSB 14 regulations.

The 3.4% difference in diameter between the two sizes indicates that the 265/70R17 has a larger diameter compared to the 265/65R17 size.

The bigger tyre diameter might cause slower acceleration and a decrease in fuel efficiency. It could even mess with the gear ratios, making the engine work harder to maintain the same speed.

Sidewall

The sidewall of a tyre significantly impacts ride comfort and handling.

For the 265/65R17 tyre size, the sidewall measures approximately 172.3mm, whereas for the 265/70R17 tyre size, it measures around 185.5.

The difference of 7.7% in sidewall height between the two sizes suggests that the 265/70R17 has a taller sidewall in comparison to the 265/65R17 size.

The taller sidewall can give you a more comfortable ride, as it can absorb more bumps on the road. However, it might also impact your tyre’s responsiveness while taking corners.

Circumference

Tyre circumference represents the distance covered by the tyre in one complete revolution.

The circumference of the 265/65R17 tyre size is roughly 2,439mm and the 265/70R17 has approximately 2,522mm. The difference in circumference between the two sizes is 3.4%.

The larger circumference of the 265/70R17 would cause your speedometer to read slightly lower than the actual speed, so you might think you’re going slower than you actually are.

Revs Per Kilometre & Speedometer Correction

Revolutions per kilometre (RPK) denotes the number of times a tyre rotates per kilometre travelled.

The 265/65R17 tyre size has approximately 410.0 revs per kilometre, while the 265/70R17 tyre size comprises around 396.5 revolution per kilometre.

The -3.3% difference means that the 265/70R17 tyres will rotate fewer times per kilometre compared to 265/65R17 tyres. As a result, your speedometer would read a bit lower than your actual speed when using the 265/70R17 tyres.

To ensure accurate speed readings, speedometer correction is necessary.

Note: If your vehicle is a Hilux, Amarok or Prado 150, check out our vehicle specific guides on the largest legal tyre size for your ride.