275/50R24 vs 265/50R24
Going from one to the other changes the overall height by -1.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/50R24 | 265/50R24 | Change |
|---|---|---|---|
| Overall height | 34.8" | 34.4" | -1.1 % |
| Sidewall | 5.41" | 5.22" | -3.6 % |
| Section width | 275 mm | 265 mm | -3.6 % |
| Circumference | 109.4" | 108.2" | -1.1 % |
| Revs per mile | 579 | 586 | +1.1 % |
| Axle height | 17.41" | 17.22" | -5.0 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 275/50R24. Fit 265/50R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.4 mph | -0.6 |
| 70 mph | 69.2 mph | -0.8 |
| 90 mph | 89.0 mph | -1.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,887 on the road, so it over-counts by 113. At a true 70 mph the first turns 676 times a minute, the second 683.