155/70R13 vs 175/60R13
Going from one to the other changes the overall height by -1.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 155/70R13 | 175/60R13 | Change |
|---|---|---|---|
| Overall height | 21.5" | 21.3" | -1.3 % |
| Sidewall | 4.27" | 4.13" | -3.2 % |
| Section width | 155 mm | 175 mm | +12.9 % |
| Circumference | 67.7" | 66.8" | -1.3 % |
| Revs per mile | 936 | 948 | +1.3 % |
| Axle height | 10.77" | 10.63" | -3.5 mm |
| Approved rim width | 4–5.5" | 5–6" | overlap 5–5.5" |
Both are approved on a rim 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 155/70R13. Fit 175/60R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.4 mph | -0.6 |
| 70 mph | 69.1 mph | -0.9 |
| 90 mph | 88.8 mph | -1.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,872 on the road, so it over-counts by 128. At a true 70 mph the first turns 1092 times a minute, the second 1106.