285/80R22.5 vs 275/80R22.5
Going from one to the other changes the overall height by -1.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 285/80R22.5 | 275/80R22.5 | Change |
|---|---|---|---|
| Overall height | 40.5" | 39.8" | -1.6 % |
| Sidewall | 8.98" | 8.66" | -3.5 % |
| Section width | 285 mm | 275 mm | -3.5 % |
| Circumference | 127.1" | 125.1" | -1.6 % |
| Revs per mile | 499 | 506 | +1.6 % |
| Axle height | 20.23" | 19.91" | -8.0 mm |
| Approved rim width | 8–10.5" | 7.5–10" | overlap 8–10" |
Both are approved on a rim 8" to 10" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 285/80R22.5. Fit 275/80R22.5 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.2 mph | -0.8 |
| 70 mph | 68.9 mph | -1.1 |
| 90 mph | 88.6 mph | -1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,844 on the road, so it over-counts by 156. At a true 70 mph the first turns 582 times a minute, the second 591.
What drivers reported
Nobody has filed a complaint naming 285/80R22.5. 275/80R22.5 carries 2.