315/30R24 vs 295/35R24
Going from one to the other changes the overall height by +2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 315/30R24 | 295/35R24 | Change |
|---|---|---|---|
| Overall height | 31.4" | 32.1" | +2.2 % |
| Sidewall | 3.72" | 4.06" | +9.3 % |
| Section width | 315 mm | 295 mm | -6.3 % |
| Circumference | 98.8" | 100.9" | +2.2 % |
| Revs per mile | 641 | 628 | -2.2 % |
| Axle height | 15.72" | 16.06" | +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 315/30R24. Fit 295/35R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.5 mph | +1.5 |
| 90 mph | 92.0 mph | +2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,219 on the road, so it under-counts by 219. At a true 70 mph the first turns 748 times a minute, the second 732.