285/45R22 vs 275/50R22
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 | 285/45R22 | 275/50R22 | Change |
|---|---|---|---|
| Overall height | 32.1" | 32.8" | +2.3 % |
| Sidewall | 5.05" | 5.41" | +7.2 % |
| Section width | 285 mm | 275 mm | -3.5 % |
| Circumference | 100.8" | 103.1" | +2.3 % |
| Revs per mile | 628 | 614 | -2.3 % |
| Axle height | 16.05" | 16.41" | +9.3 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 285/45R22. Fit 275/50R22 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 10,227 on the road, so it under-counts by 227. At a true 70 mph the first turns 733 times a minute, the second 717.