345/25R24 vs 335/25R24
Going from one to the other changes the overall height by -0.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 345/25R24 | 335/25R24 | Change |
|---|---|---|---|
| Overall height | 30.8" | 30.6" | -0.6 % |
| Sidewall | 3.40" | 3.30" | -2.9 % |
| Section width | 345 mm | 335 mm | -2.9 % |
| Circumference | 96.7" | 96.1" | -0.6 % |
| Revs per mile | 655 | 659 | +0.6 % |
| Axle height | 15.40" | 15.30" | -2.5 mm |
| Approved rim width | 9.5–12.5" | 9.5–12.5" | overlap 9.5–12.5" |
Both are approved on a rim 9.5" to 12.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 345/25R24. Fit 335/25R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.8 mph | -0.2 |
| 50 mph | 49.7 mph | -0.3 |
| 70 mph | 69.6 mph | -0.4 |
| 90 mph | 89.4 mph | -0.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,936 on the road, so it over-counts by 64. At a true 70 mph the first turns 764 times a minute, the second 769.