305/35R22 vs 295/35R22
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 | 305/35R22 | 295/35R22 | Change |
|---|---|---|---|
| Overall height | 30.4" | 30.1" | -0.9 % |
| Sidewall | 4.20" | 4.06" | -3.3 % |
| Section width | 305 mm | 295 mm | -3.3 % |
| Circumference | 95.5" | 94.7" | -0.9 % |
| Revs per mile | 663 | 669 | +0.9 % |
| Axle height | 15.20" | 15.06" | -3.5 mm |
| Approved rim width | 8.5–11" | 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 305/35R22. Fit 295/35R22 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 | 69.4 mph | -0.6 |
| 90 mph | 89.2 mph | -0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,909 on the road, so it over-counts by 91. At a true 70 mph the first turns 774 times a minute, the second 781.