165/55R16 vs 145/65R16
Going from one to the other changes the overall height by +1.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 165/55R16 | 145/65R16 | Change |
|---|---|---|---|
| Overall height | 23.1" | 23.4" | +1.2 % |
| Sidewall | 3.57" | 3.71" | +3.9 % |
| Section width | 165 mm | 145 mm | -12.1 % |
| Circumference | 72.7" | 73.6" | +1.2 % |
| Revs per mile | 871 | 861 | -1.2 % |
| Axle height | 11.57" | 11.71" | +3.5 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 165/55R16. Fit 145/65R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.4 mph | +0.4 |
| 50 mph | 50.6 mph | +0.6 |
| 70 mph | 70.8 mph | +0.8 |
| 90 mph | 91.1 mph | +1.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,119 on the road, so it under-counts by 119. At a true 70 mph the first turns 1017 times a minute, the second 1005.