245/80R22 vs 265/70R22
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 245/80R22 | 265/70R22 | Change |
|---|---|---|---|
| Overall height | 37.4" | 36.6" | -2.2 % |
| Sidewall | 7.72" | 7.30" | -5.4 % |
| Section width | 245 mm | 265 mm | +8.2 % |
| Circumference | 117.6" | 115.0" | -2.2 % |
| Revs per mile | 539 | 551 | +2.2 % |
| Axle height | 18.72" | 18.30" | -10.5 mm |
| Approved rim width | 7–9" | 7.5–9.5" | 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 245/80R22. Fit 265/70R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.5 mph | -1.5 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,779 on the road, so it over-counts by 221. At a true 70 mph the first turns 629 times a minute, the second 643.