255/30R22 vs 275/30R22
Going from one to the other changes the overall height by +1.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/30R22 | 275/30R22 | Change |
|---|---|---|---|
| Overall height | 28.0" | 28.5" | +1.7 % |
| Sidewall | 3.01" | 3.25" | +7.8 % |
| Section width | 255 mm | 275 mm | +7.8 % |
| Circumference | 88.0" | 89.5" | +1.7 % |
| Revs per mile | 720 | 708 | -1.7 % |
| Axle height | 14.01" | 14.25" | +6.0 mm |
| Approved rim width | 7–9.5" | 7.5–10" | 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 255/30R22. Fit 275/30R22 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 | 71.2 mph | +1.2 |
| 90 mph | 91.5 mph | +1.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,169 on the road, so it under-counts by 169. At a true 70 mph the first turns 840 times a minute, the second 826.
What drivers reported
255/30R22 carries 1 complaints. Nobody has filed one naming 275/30R22.