205/75R16 vs 195/80R16
Going from one to the other changes the overall height by +0.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/75R16 | 195/80R16 | Change |
|---|---|---|---|
| Overall height | 28.1" | 28.3" | +0.6 % |
| Sidewall | 6.05" | 6.14" | +1.5 % |
| Section width | 205 mm | 195 mm | -4.9 % |
| Circumference | 88.3" | 88.9" | +0.6 % |
| Revs per mile | 718 | 713 | -0.6 % |
| Axle height | 14.05" | 14.14" | +2.3 mm |
| Approved rim width | 5.5–7.5" | 5.5–7" | overlap 5.5–7" |
Both are approved on a rim 5.5" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 205/75R16. Fit 195/80R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.2 mph | +0.2 |
| 50 mph | 50.3 mph | +0.3 |
| 70 mph | 70.4 mph | +0.4 |
| 90 mph | 90.6 mph | +0.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,063 on the road, so it under-counts by 63. At a true 70 mph the first turns 837 times a minute, the second 832.