145/70R13 vs 155/65R13
Going from one to the other changes the overall height by -0.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 145/70R13 | 155/65R13 | Change |
|---|---|---|---|
| Overall height | 21.0" | 20.9" | -0.3 % |
| Sidewall | 4.00" | 3.97" | -0.7 % |
| Section width | 145 mm | 155 mm | +6.9 % |
| Circumference | 65.9" | 65.8" | -0.3 % |
| Revs per mile | 961 | 963 | +0.3 % |
| Axle height | 10.50" | 10.47" | -0.8 mm |
| Approved rim width | 4–5.5" | 4–5.5" | overlap 4–5.5" |
Both are approved on a rim 4" 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 145/70R13. Fit 155/65R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.9 mph | -0.1 |
| 50 mph | 49.9 mph | -0.1 |
| 70 mph | 69.8 mph | -0.2 |
| 90 mph | 89.7 mph | -0.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,972 on the road, so it over-counts by 28. At a true 70 mph the first turns 1121 times a minute, the second 1124.