135/70R15 vs 155/60R15
Going from one to the other changes the overall height by -0.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 135/70R15 | 155/60R15 | Change |
|---|---|---|---|
| Overall height | 22.4" | 22.3" | -0.5 % |
| Sidewall | 3.72" | 3.66" | -1.6 % |
| Section width | 135 mm | 155 mm | +14.8 % |
| Circumference | 70.5" | 70.1" | -0.5 % |
| Revs per mile | 899 | 903 | +0.5 % |
| Axle height | 11.22" | 11.16" | -1.5 mm |
| Approved rim width | 3.5–5" | 4–5.5" | overlap 4–5" |
Both are approved on a rim 4" to 5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 135/70R15. Fit 155/60R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.8 mph | -0.2 |
| 50 mph | 49.7 mph | -0.3 |
| 70 mph | 69.6 mph | -0.4 |
| 90 mph | 89.5 mph | -0.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,947 on the road, so it over-counts by 53. At a true 70 mph the first turns 1049 times a minute, the second 1054.
What drivers reported
135/70R15 carries 2 complaints. Nobody has filed one naming 155/60R15.