265/55R24 vs 275/50R24
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 | 265/55R24 | 275/50R24 | Change |
|---|---|---|---|
| Overall height | 35.5" | 34.8" | -1.8 % |
| Sidewall | 5.74" | 5.41" | -5.7 % |
| Section width | 265 mm | 275 mm | +3.8 % |
| Circumference | 111.5" | 109.4" | -1.8 % |
| Revs per mile | 568 | 579 | +1.8 % |
| Axle height | 17.74" | 17.41" | -8.3 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 265/55R24. Fit 275/50R24 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 | 68.7 mph | -1.3 |
| 90 mph | 88.4 mph | -1.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,817 on the road, so it over-counts by 183. At a true 70 mph the first turns 663 times a minute, the second 676.