165/60R14 vs 145/65R14
Going from one to the other changes the overall height by -1.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 165/60R14 | 145/65R14 | Change |
|---|---|---|---|
| Overall height | 21.8" | 21.4" | -1.7 % |
| Sidewall | 3.90" | 3.71" | -4.8 % |
| Section width | 165 mm | 145 mm | -12.1 % |
| Circumference | 68.5" | 67.3" | -1.7 % |
| Revs per mile | 925 | 941 | +1.7 % |
| Axle height | 10.90" | 10.71" | -4.8 mm |
| Approved rim width | 4.5–6" | 4–5.5" | overlap 4.5–5.5" |
Both are approved on a rim 4.5" to 5.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 165/60R14. Fit 145/65R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.1 mph | -0.9 |
| 70 mph | 68.8 mph | -1.2 |
| 90 mph | 88.5 mph | -1.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,828 on the road, so it over-counts by 172. At a true 70 mph the first turns 1080 times a minute, the second 1098.