175/55R16 vs 195/50R16
Going from one to the other changes the overall height by +0.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/55R16 | 195/50R16 | Change |
|---|---|---|---|
| Overall height | 23.6" | 23.7" | +0.4 % |
| Sidewall | 3.79" | 3.84" | +1.3 % |
| Section width | 175 mm | 195 mm | +11.4 % |
| Circumference | 74.1" | 74.4" | +0.4 % |
| Revs per mile | 855 | 852 | -0.4 % |
| Axle height | 11.79" | 11.84" | +1.3 mm |
| Approved rim width | 5–6" | 5.5–7" | overlap 5.5–6" |
Both are approved on a rim 5.5" to 6" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 175/55R16. Fit 195/50R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.1 mph | +0.1 |
| 50 mph | 50.2 mph | +0.2 |
| 70 mph | 70.3 mph | +0.3 |
| 90 mph | 90.4 mph | +0.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,042 on the road, so it under-counts by 42. At a true 70 mph the first turns 998 times a minute, the second 994.