265/70R22 vs 245/80R22
Going from one to the other changes the overall height by +2.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 265/70R22 | 245/80R22 | Change |
|---|---|---|---|
| Overall height | 36.6" | 37.4" | +2.3 % |
| Sidewall | 7.30" | 7.72" | +5.7 % |
| Section width | 265 mm | 245 mm | -7.5 % |
| Circumference | 115.0" | 117.6" | +2.3 % |
| Revs per mile | 551 | 539 | -2.3 % |
| Axle height | 18.30" | 18.72" | +10.5 mm |
| Approved rim width | 7.5–9.5" | 7–9" | overlap 7.5–9" |
Both are approved on a rim 7.5" to 9" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 265/70R22. Fit 245/80R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.6 mph | +1.6 |
| 90 mph | 92.0 mph | +2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,226 on the road, so it under-counts by 226. At a true 70 mph the first turns 643 times a minute, the second 629.