175/60R17 vs 155/65R17
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 | 175/60R17 | 155/65R17 | Change |
|---|---|---|---|
| Overall height | 25.3" | 24.9" | -1.3 % |
| Sidewall | 4.13" | 3.97" | -4.0 % |
| Section width | 175 mm | 155 mm | -11.4 % |
| Circumference | 79.4" | 78.3" | -1.3 % |
| Revs per mile | 798 | 809 | +1.3 % |
| Axle height | 12.63" | 12.47" | -4.3 mm |
| Approved rim width | 5–6" | 4–5.5" | 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 175/60R17. Fit 155/65R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.3 mph | -0.7 |
| 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 9,868 on the road, so it over-counts by 132. At a true 70 mph the first turns 931 times a minute, the second 944.
What drivers reported
175/60R17 carries 2 complaints. Nobody has filed one naming 155/65R17.