275/55R17 vs 265/60R17
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/55R17 | 265/60R17 | Change |
|---|---|---|---|
| Overall height | 28.9" | 29.5" | +2.1 % |
| Sidewall | 5.95" | 6.26" | +5.1 % |
| Section width | 275 mm | 265 mm | -3.6 % |
| Circumference | 90.8" | 92.7" | +2.1 % |
| Revs per mile | 698 | 683 | -2.1 % |
| Axle height | 14.45" | 14.76" | +7.8 mm |
| Approved rim width | 7.5–10" | 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 275/55R17. Fit 265/60R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.5 mph | +1.5 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,211 on the road, so it under-counts by 211. At a true 70 mph the first turns 814 times a minute, the second 797.