255/65R17 vs 265/60R17
Going from one to the other changes the overall height by -1.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/65R17 | 265/60R17 | Change |
|---|---|---|---|
| Overall height | 30.1" | 29.5" | -1.8 % |
| Sidewall | 6.53" | 6.26" | -4.1 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 94.4" | 92.7" | -1.8 % |
| Revs per mile | 671 | 683 | +1.8 % |
| Axle height | 15.03" | 14.76" | -6.8 mm |
| Approved rim width | 7–9.5" | 7.5–9.5" | overlap 7.5–9.5" |
Both are approved on a rim 7.5" to 9.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 255/65R17. Fit 265/60R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.1 mph | -0.9 |
| 70 mph | 68.8 mph | -1.2 |
| 90 mph | 88.4 mph | -1.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,823 on the road, so it over-counts by 177. At a true 70 mph the first turns 783 times a minute, the second 797.