275/80R22.5 vs 285/80R22.5
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 | 275/80R22.5 | 285/80R22.5 | Change |
|---|---|---|---|
| Overall height | 39.8" | 40.5" | +1.6 % |
| Sidewall | 8.66" | 8.98" | +3.6 % |
| Section width | 275 mm | 285 mm | +3.6 % |
| Circumference | 125.1" | 127.1" | +1.6 % |
| Revs per mile | 506 | 499 | -1.6 % |
| Axle height | 19.91" | 20.23" | +8.0 mm |
| Approved rim width | 7.5–10" | 8–10.5" | 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 275/80R22.5. Fit 285/80R22.5 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 50 mph | 50.8 mph | +0.8 |
| 70 mph | 71.1 mph | +1.1 |
| 90 mph | 91.4 mph | +1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,158 on the road, so it under-counts by 158. At a true 70 mph the first turns 591 times a minute, the second 582.
What drivers reported
275/80R22.5 carries 2 complaints. Nobody has filed one naming 285/80R22.5.