195/40R16 vs 205/40R16
Going from one to the other changes the overall height by +1.4 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/40R16 | 205/40R16 | Change |
|---|---|---|---|
| Overall height | 22.1" | 22.5" | +1.4 % |
| Sidewall | 3.07" | 3.23" | +5.1 % |
| Section width | 195 mm | 205 mm | +5.1 % |
| Circumference | 69.6" | 70.5" | +1.4 % |
| Revs per mile | 911 | 898 | -1.4 % |
| Axle height | 11.07" | 11.23" | +4.0 mm |
| Approved rim width | 5.5–7" | 5.5–7.5" | 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 195/40R16. Fit 205/40R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.4 mph | +0.4 |
| 50 mph | 50.7 mph | +0.7 |
| 70 mph | 71.0 mph | +1.0 |
| 90 mph | 91.3 mph | +1.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,142 on the road, so it under-counts by 142. At a true 70 mph the first turns 1063 times a minute, the second 1048.