195/65R15 vs 205/55R16
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 | 195/65R15 | 205/55R16 | Change |
|---|---|---|---|
| Overall height | 25.0" | 24.9" | -0.4 % |
| Sidewall | 4.99" | 4.44" | -11.0 % |
| Section width | 195 mm | 205 mm | +5.1 % |
| Circumference | 78.5" | 78.2" | -0.4 % |
| Revs per mile | 807 | 811 | +0.4 % |
| Axle height | 12.49" | 12.44" | -1.3 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 195/65R15. Fit 205/55R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.9 mph | -0.1 |
| 50 mph | 49.8 mph | -0.2 |
| 70 mph | 69.7 mph | -0.3 |
| 90 mph | 89.6 mph | -0.4 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,959 on the road, so it over-counts by 41. At a true 70 mph the first turns 942 times a minute, the second 946.