185/60R14 vs 165/65R14
Going from one to the other changes the overall height by -1.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 185/60R14 | 165/65R14 | Change |
|---|---|---|---|
| Overall height | 22.7" | 22.4" | -1.3 % |
| Sidewall | 4.37" | 4.22" | -3.4 % |
| Section width | 185 mm | 165 mm | -10.8 % |
| Circumference | 71.4" | 70.5" | -1.3 % |
| Revs per mile | 887 | 899 | +1.3 % |
| Axle height | 11.37" | 11.22" | -3.8 mm |
| Approved rim width | 5–6.5" | 4.5–6" | overlap 5–6" |
Both are approved on a rim 5" to 6" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 185/60R14. Fit 165/65R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.4 mph | -0.6 |
| 70 mph | 69.1 mph | -0.9 |
| 90 mph | 88.8 mph | -1.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,870 on the road, so it over-counts by 130. At a true 70 mph the first turns 1035 times a minute, the second 1048.