325/60R17 vs 335/55R17
Going from one to the other changes the overall height by -2.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 325/60R17 | 335/55R17 | Change |
|---|---|---|---|
| Overall height | 32.4" | 31.5" | -2.6 % |
| Sidewall | 7.68" | 7.25" | -5.5 % |
| Section width | 325 mm | 335 mm | +3.1 % |
| Circumference | 101.6" | 99.0" | -2.6 % |
| Revs per mile | 623 | 640 | +2.6 % |
| Axle height | 16.18" | 15.75" | -10.8 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 325/60R17. Fit 335/55R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.2 mph | -0.8 |
| 50 mph | 48.7 mph | -1.3 |
| 70 mph | 68.2 mph | -1.8 |
| 90 mph | 87.6 mph | -2.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,738 on the road, so it over-counts by 262. At a true 70 mph the first turns 727 times a minute, the second 747.