255/35R22 vs 245/35R22
Going from one to the other changes the overall height by -0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 255/35R22 | 245/35R22 | Change |
|---|---|---|---|
| Overall height | 29.0" | 28.8" | -0.9 % |
| Sidewall | 3.51" | 3.38" | -3.9 % |
| Section width | 255 mm | 245 mm | -3.9 % |
| Circumference | 91.2" | 90.3" | -0.9 % |
| Revs per mile | 695 | 701 | +0.9 % |
| Axle height | 14.51" | 14.38" | -3.5 mm |
| Approved rim width | 7–9.5" | 7–9" | overlap 7–9" |
Both are approved on a rim 7" to 9" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 255/35R22. Fit 245/35R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.1 mph | -0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,905 on the road, so it over-counts by 95. At a true 70 mph the first turns 811 times a minute, the second 818.
What drivers reported
Nobody has filed a complaint naming 255/35R22. 245/35R22 carries 1.