315/30R22 vs 295/35R22
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 | 315/30R22 | 295/35R22 | Change |
|---|---|---|---|
| Overall height | 29.4" | 30.1" | +2.3 % |
| Sidewall | 3.72" | 4.06" | +9.3 % |
| Section width | 315 mm | 295 mm | -6.3 % |
| Circumference | 92.5" | 94.7" | +2.3 % |
| Revs per mile | 685 | 669 | -2.3 % |
| Axle height | 14.72" | 15.06" | +8.8 mm |
| Approved rim width | 8.5–11.5" | 8.5–11" | overlap 8.5–11" |
Both are approved on a rim 8.5" to 11" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 315/30R22. Fit 295/35R22 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.6 mph | +1.6 |
| 90 mph | 92.1 mph | +2.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,234 on the road, so it under-counts by 234. At a true 70 mph the first turns 799 times a minute, the second 781.