255/50R24 vs 265/45R24
Going from one to the other changes the overall height by -1.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/50R24 | 265/45R24 | Change |
|---|---|---|---|
| Overall height | 34.0" | 33.4" | -1.9 % |
| Sidewall | 5.02" | 4.69" | -6.5 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 106.9" | 104.9" | -1.9 % |
| Revs per mile | 592 | 604 | +1.9 % |
| Axle height | 17.02" | 16.69" | -8.3 mm |
| Approved rim width | 7–9.5" | 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 255/50R24. Fit 265/45R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.4 mph | -0.6 |
| 50 mph | 49.0 mph | -1.0 |
| 70 mph | 68.7 mph | -1.3 |
| 90 mph | 88.3 mph | -1.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,809 on the road, so it over-counts by 191. At a true 70 mph the first turns 691 times a minute, the second 705.