255/75R19 vs 265/75R19
Going from one to the other changes the overall height by +1.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/75R19 | 265/75R19 | Change |
|---|---|---|---|
| Overall height | 34.1" | 34.6" | +1.7 % |
| Sidewall | 7.53" | 7.82" | +3.9 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 107.0" | 108.9" | +1.7 % |
| Revs per mile | 592 | 582 | -1.7 % |
| Axle height | 17.03" | 17.32" | +7.5 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 255/75R19. Fit 265/75R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 50 mph | 50.9 mph | +0.9 |
| 70 mph | 71.2 mph | +1.2 |
| 90 mph | 91.6 mph | +1.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,173 on the road, so it under-counts by 173. At a true 70 mph the first turns 691 times a minute, the second 679.