225/70R14 vs 235/65R14
Going from one to the other changes the overall height by -1.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 225/70R14 | 235/65R14 | Change |
|---|---|---|---|
| Overall height | 26.4" | 26.0" | -1.4 % |
| Sidewall | 6.20" | 6.01" | -3.0 % |
| Section width | 225 mm | 235 mm | +4.4 % |
| Circumference | 82.9" | 81.8" | -1.4 % |
| Revs per mile | 764 | 775 | +1.4 % |
| Axle height | 13.20" | 13.01" | -4.8 mm |
| Approved rim width | 6–8.5" | 6.5–8.5" | 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 225/70R14. Fit 235/65R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.3 mph | -0.7 |
| 70 mph | 69.0 mph | -1.0 |
| 90 mph | 88.7 mph | -1.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,858 on the road, so it over-counts by 142. At a true 70 mph the first turns 891 times a minute, the second 904.
What drivers reported
225/70R14 carries 20 complaints and 1 deaths. Nobody has filed one naming 235/65R14.