185/60R13 vs 195/60R13
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 | 185/60R13 | 195/60R13 | Change |
|---|---|---|---|
| Overall height | 21.7" | 22.2" | +2.2 % |
| Sidewall | 4.37" | 4.61" | +5.4 % |
| Section width | 185 mm | 195 mm | +5.4 % |
| Circumference | 68.3" | 69.8" | +2.2 % |
| Revs per mile | 928 | 908 | -2.2 % |
| Axle height | 10.87" | 11.11" | +6.0 mm |
| Approved rim width | 5–6.5" | 5.5–7" | overlap 5.5–6.5" |
Both are approved on a rim 5.5" to 6.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 185/60R13. Fit 195/60R13 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.5 mph | +1.5 |
| 90 mph | 92.0 mph | +2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,217 on the road, so it under-counts by 217. At a true 70 mph the first turns 1082 times a minute, the second 1059.