185/65R14 vs 165/70R14
Going from one to the other changes the overall height by -1.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 185/65R14 | 165/70R14 | Change |
|---|---|---|---|
| Overall height | 23.5" | 23.1" | -1.6 % |
| Sidewall | 4.73" | 4.55" | -4.0 % |
| Section width | 185 mm | 165 mm | -10.8 % |
| Circumference | 73.7" | 72.6" | -1.6 % |
| Revs per mile | 859 | 873 | +1.6 % |
| Axle height | 11.73" | 11.55" | -4.8 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 185/65R14. Fit 165/70R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.5 mph | -0.5 |
| 50 mph | 49.2 mph | -0.8 |
| 70 mph | 68.9 mph | -1.1 |
| 90 mph | 88.6 mph | -1.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,841 on the road, so it over-counts by 159. At a true 70 mph the first turns 1003 times a minute, the second 1019.
What drivers reported
185/65R14 carries 76 complaints. Nobody has filed one naming 165/70R14.