195/55R17 vs 205/50R17
Going from one to the other changes the overall height by -1.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/55R17 | 205/50R17 | Change |
|---|---|---|---|
| Overall height | 25.4" | 25.1" | -1.5 % |
| Sidewall | 4.22" | 4.04" | -4.4 % |
| Section width | 195 mm | 205 mm | +5.1 % |
| Circumference | 79.9" | 78.8" | -1.5 % |
| Revs per mile | 793 | 804 | +1.5 % |
| Axle height | 12.72" | 12.54" | -4.8 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 195/55R17. Fit 205/50R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.6 mph | -0.4 |
| 50 mph | 49.3 mph | -0.7 |
| 70 mph | 69.0 mph | -1.0 |
| 90 mph | 88.7 mph | -1.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,853 on the road, so it over-counts by 147. At a true 70 mph the first turns 925 times a minute, the second 939.
What drivers reported
Nobody has filed a complaint naming 195/55R17. 205/50R17 carries 71.