255/80R22.5 vs 265/75R22.5
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 | 255/80R22.5 | 265/75R22.5 | Change |
|---|---|---|---|
| Overall height | 38.6" | 38.1" | -1.1 % |
| Sidewall | 8.03" | 7.82" | -2.6 % |
| Section width | 255 mm | 265 mm | +3.9 % |
| Circumference | 121.1" | 119.9" | -1.1 % |
| Revs per mile | 523 | 529 | +1.1 % |
| Axle height | 19.28" | 19.07" | -5.3 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 255/80R22.5. Fit 265/75R22.5 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 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 9,893 on the road, so it over-counts by 107. At a true 70 mph the first turns 610 times a minute, the second 617.
What drivers reported
255/80R22.5 carries 42 complaints. Nobody has filed one naming 265/75R22.5.