135/80R13 vs 155/65R13
Going from one to the other changes the overall height by -2.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 135/80R13 | 155/65R13 | Change |
|---|---|---|---|
| Overall height | 21.5" | 20.9" | -2.7 % |
| Sidewall | 4.25" | 3.97" | -6.7 % |
| Section width | 135 mm | 155 mm | +14.8 % |
| Circumference | 67.6" | 65.8" | -2.7 % |
| Revs per mile | 938 | 963 | +2.7 % |
| Axle height | 10.75" | 10.47" | -7.3 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 135/80R13. Fit 155/65R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.2 mph | -0.8 |
| 50 mph | 48.7 mph | -1.3 |
| 70 mph | 68.1 mph | -1.9 |
| 90 mph | 87.6 mph | -2.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,735 on the road, so it over-counts by 265. At a true 70 mph the first turns 1094 times a minute, the second 1124.