185/80R14 vs 195/80R14
Going from one to the other changes the overall height by +2.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 185/80R14 | 195/80R14 | Change |
|---|---|---|---|
| Overall height | 25.7" | 26.3" | +2.5 % |
| Sidewall | 5.83" | 6.14" | +5.4 % |
| Section width | 185 mm | 195 mm | +5.4 % |
| Circumference | 80.6" | 82.6" | +2.5 % |
| Revs per mile | 786 | 767 | -2.5 % |
| Axle height | 12.83" | 13.14" | +8.0 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 185/80R14. Fit 195/80R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.7 mph | +1.7 |
| 90 mph | 92.2 mph | +2.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,246 on the road, so it under-counts by 246. At a true 70 mph the first turns 917 times a minute, the second 895.