135/85R13 vs 155/70R13
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 135/85R13 | 155/70R13 | Change |
|---|---|---|---|
| Overall height | 22.0" | 21.5" | -2.2 % |
| Sidewall | 4.52" | 4.27" | -5.4 % |
| Section width | 135 mm | 155 mm | +14.8 % |
| Circumference | 69.2" | 67.7" | -2.2 % |
| Revs per mile | 915 | 936 | +2.2 % |
| Axle height | 11.02" | 10.77" | -6.3 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 135/85R13. Fit 155/70R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.4 mph | -1.6 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,777 on the road, so it over-counts by 223. At a true 70 mph the first turns 1068 times a minute, the second 1092.