275/50R22 vs 255/50R22
Going from one to the other changes the overall height by -2.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 275/50R22 | 255/50R22 | Change |
|---|---|---|---|
| Overall height | 32.8" | 32.0" | -2.4 % |
| Sidewall | 5.41" | 5.02" | -7.3 % |
| Section width | 275 mm | 255 mm | -7.3 % |
| Circumference | 103.1" | 100.7" | -2.4 % |
| Revs per mile | 614 | 629 | +2.4 % |
| Axle height | 16.41" | 16.02" | -10.0 mm |
| Approved rim width | 7.5–10" | 7–9.5" | overlap 7.5–9.5" |
Both are approved on a rim 7.5" to 9.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 275/50R22. Fit 255/50R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.8 mph | -1.2 |
| 70 mph | 68.3 mph | -1.7 |
| 90 mph | 87.8 mph | -2.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,760 on the road, so it over-counts by 240. At a true 70 mph the first turns 717 times a minute, the second 734.
What drivers reported
275/50R22 carries 2 complaints. Nobody has filed one naming 255/50R22.