195/70R14 vs 175/80R14
Going from one to the other changes the overall height by +1.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/70R14 | 175/80R14 | Change |
|---|---|---|---|
| Overall height | 24.7" | 25.0" | +1.1 % |
| Sidewall | 5.37" | 5.51" | +2.6 % |
| Section width | 195 mm | 175 mm | -10.3 % |
| Circumference | 77.7" | 78.6" | +1.1 % |
| Revs per mile | 815 | 806 | -1.1 % |
| Axle height | 12.37" | 12.51" | +3.5 mm |
| Approved rim width | 5.5–7" | 5–6" | overlap 5.5–6" |
Both are approved on a rim 5.5" to 6" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 195/70R14. Fit 175/80R14 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.6 mph | +0.6 |
| 70 mph | 70.8 mph | +0.8 |
| 90 mph | 91.0 mph | +1.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,111 on the road, so it under-counts by 111. At a true 70 mph the first turns 951 times a minute, the second 940.