325/40R24 vs 335/35R24
Going from one to the other changes the overall height by -2.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 325/40R24 | 335/35R24 | Change |
|---|---|---|---|
| Overall height | 34.2" | 33.2" | -2.9 % |
| Sidewall | 5.12" | 4.62" | -9.8 % |
| Section width | 325 mm | 335 mm | +3.1 % |
| Circumference | 107.6" | 104.4" | -2.9 % |
| Revs per mile | 589 | 607 | +2.9 % |
| Axle height | 17.12" | 16.62" | -12.8 mm |
| Approved rim width | 9–12" | 9.5–12.5" | overlap 9.5–12" |
Both are approved on a rim 9.5" to 12" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 325/40R24. Fit 335/35R24 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.1 mph | -0.9 |
| 50 mph | 48.5 mph | -1.5 |
| 70 mph | 67.9 mph | -2.1 |
| 90 mph | 87.4 mph | -2.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,707 on the road, so it over-counts by 293. At a true 70 mph the first turns 687 times a minute, the second 708.