175/70R14 vs 165/70R14
Going from one to the other changes the overall height by -2.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/70R14 | 165/70R14 | Change |
|---|---|---|---|
| Overall height | 23.6" | 23.1" | -2.3 % |
| Sidewall | 4.82" | 4.55" | -5.7 % |
| Section width | 175 mm | 165 mm | -5.7 % |
| Circumference | 74.3" | 72.6" | -2.3 % |
| Revs per mile | 853 | 873 | +2.3 % |
| Axle height | 11.82" | 11.55" | -7.0 mm |
| Approved rim width | 5–6" | 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 175/70R14. Fit 165/70R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.8 mph | -1.2 |
| 70 mph | 68.4 mph | -1.6 |
| 90 mph | 87.9 mph | -2.1 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,767 on the road, so it over-counts by 233. At a true 70 mph the first turns 995 times a minute, the second 1019.
What drivers reported
175/70R14 carries 1 complaints. Nobody has filed one naming 165/70R14.