245/60R24 vs 265/55R24
Going from one to the other changes the overall height by -0.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 245/60R24 | 265/55R24 | Change |
|---|---|---|---|
| Overall height | 35.6" | 35.5" | -0.3 % |
| Sidewall | 5.79" | 5.74" | -0.9 % |
| Section width | 245 mm | 265 mm | +8.2 % |
| Circumference | 111.8" | 111.5" | -0.3 % |
| Revs per mile | 567 | 568 | +0.3 % |
| Axle height | 17.79" | 17.74" | -1.3 mm |
| Approved rim width | 7–9" | 7.5–9.5" | overlap 7.5–9" |
Both are approved on a rim 7.5" to 9" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 245/60R24. Fit 265/55R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.9 mph | -0.1 |
| 50 mph | 49.9 mph | -0.1 |
| 70 mph | 69.8 mph | -0.2 |
| 90 mph | 89.8 mph | -0.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,972 on the road, so it over-counts by 28. At a true 70 mph the first turns 661 times a minute, the second 663.