265/65R23 vs 275/60R23
Going from one to the other changes the overall height by -1.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 265/65R23 | 275/60R23 | Change |
|---|---|---|---|
| Overall height | 36.6" | 36.0" | -1.6 % |
| Sidewall | 6.78" | 6.50" | -4.2 % |
| Section width | 265 mm | 275 mm | +3.8 % |
| Circumference | 114.9" | 113.1" | -1.6 % |
| Revs per mile | 552 | 560 | +1.6 % |
| Axle height | 18.28" | 18.00" | -7.3 mm |
| Approved rim width | 7.5–9.5" | 7.5–10" | 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 265/65R23. Fit 275/60R23 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.2 mph | -0.8 |
| 70 mph | 68.9 mph | -1.1 |
| 90 mph | 88.6 mph | -1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,844 on the road, so it over-counts by 156. At a true 70 mph the first turns 644 times a minute, the second 654.