145/75R13 vs 165/70R13
Going from one to the other changes the overall height by +2.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 145/75R13 | 165/70R13 | Change |
|---|---|---|---|
| Overall height | 21.6" | 22.1" | +2.5 % |
| Sidewall | 4.28" | 4.55" | +6.2 % |
| Section width | 145 mm | 165 mm | +13.8 % |
| Circumference | 67.7" | 69.4" | +2.5 % |
| Revs per mile | 935 | 913 | -2.5 % |
| Axle height | 10.78" | 11.05" | +6.8 mm |
| Approved rim width | 4–5.5" | 4.5–6" | 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 145/75R13. Fit 165/70R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.7 mph | +1.7 |
| 90 mph | 92.2 mph | +2.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,246 on the road, so it under-counts by 246. At a true 70 mph the first turns 1091 times a minute, the second 1065.
What drivers reported
Nobody has filed a complaint naming 145/75R13. 165/70R13 carries 2.