235/55R14 vs 225/60R14
Going from one to the other changes the overall height by +1.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 235/55R14 | 225/60R14 | Change |
|---|---|---|---|
| Overall height | 24.2" | 24.6" | +1.9 % |
| Sidewall | 5.09" | 5.31" | +4.4 % |
| Section width | 235 mm | 225 mm | -4.3 % |
| Circumference | 76.0" | 77.4" | +1.9 % |
| Revs per mile | 834 | 819 | -1.9 % |
| Axle height | 12.09" | 12.31" | +5.8 mm |
| Approved rim width | 6.5–8.5" | 6–8.5" | overlap 6.5–8.5" |
Both are approved on a rim 6.5" to 8.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 235/55R14. Fit 225/60R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 50.9 mph | +0.9 |
| 70 mph | 71.3 mph | +1.3 |
| 90 mph | 91.7 mph | +1.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,187 on the road, so it under-counts by 187. At a true 70 mph the first turns 973 times a minute, the second 955.