185/55R14 vs 165/60R14
Going from one to the other changes the overall height by -1.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 185/55R14 | 165/60R14 | Change |
|---|---|---|---|
| Overall height | 22.0" | 21.8" | -1.0 % |
| Sidewall | 4.01" | 3.90" | -2.7 % |
| Section width | 185 mm | 165 mm | -10.8 % |
| Circumference | 69.2" | 68.5" | -1.0 % |
| Revs per mile | 916 | 925 | +1.0 % |
| Axle height | 11.01" | 10.90" | -2.8 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 185/55R14. Fit 165/60R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.1 mph | -0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,902 on the road, so it over-counts by 98. At a true 70 mph the first turns 1069 times a minute, the second 1080.