175/55R16 vs 175/50R16
Going from one to the other changes the overall height by -2.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/55R16 | 175/50R16 | Change |
|---|---|---|---|
| Overall height | 23.6" | 22.9" | -2.9 % |
| Sidewall | 3.79" | 3.44" | -9.1 % |
| Section width | 175 mm | 175 mm | 0.0 % |
| Circumference | 74.1" | 71.9" | -2.9 % |
| Revs per mile | 855 | 881 | +2.9 % |
| Axle height | 11.79" | 11.44" | -8.8 mm |
| Approved rim width | 5–6" | 5–6" | overlap 5–6" |
Both are approved on a rim 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 175/50R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.1 mph | -0.9 |
| 50 mph | 48.5 mph | -1.5 |
| 70 mph | 68.0 mph | -2.0 |
| 90 mph | 87.4 mph | -2.6 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,708 on the road, so it over-counts by 292. At a true 70 mph the first turns 998 times a minute, the second 1028.
What drivers reported
175/55R16 carries 1 complaints. Nobody has filed one naming 175/50R16.