255/30R22 vs 235/35R22
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 | 255/30R22 | 235/35R22 | Change |
|---|---|---|---|
| Overall height | 28.0" | 28.5" | +1.6 % |
| Sidewall | 3.01" | 3.24" | +7.5 % |
| Section width | 255 mm | 235 mm | -7.8 % |
| Circumference | 88.0" | 89.5" | +1.6 % |
| Revs per mile | 720 | 708 | -1.6 % |
| Axle height | 14.01" | 14.24" | +5.8 mm |
| Approved rim width | 7–9.5" | 6.5–8.5" | overlap 7–8.5" |
Both are approved on a rim 7" to 8.5" 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 235/35R22 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 | 91.5 mph | +1.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,162 on the road, so it under-counts by 162. 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 235/35R22.