175/80R15 vs 195/75R15
Going from one to the other changes the overall height by +1.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/80R15 | 195/75R15 | Change |
|---|---|---|---|
| Overall height | 26.0" | 26.5" | +1.9 % |
| Sidewall | 5.51" | 5.76" | +4.5 % |
| Section width | 175 mm | 195 mm | +11.4 % |
| Circumference | 81.8" | 83.3" | +1.9 % |
| Revs per mile | 775 | 761 | -1.9 % |
| Axle height | 13.01" | 13.26" | +6.3 mm |
| Approved rim width | 5–6" | 5.5–7" | 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 175/80R15. Fit 195/75R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 50.9 mph | +0.9 |
| 70 mph | 71.3 mph | +1.3 |
| 90 mph | 91.7 mph | +1.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,189 on the road, so it under-counts by 189. At a true 70 mph the first turns 904 times a minute, the second 887.
What drivers reported
Nobody has filed a complaint naming 175/80R15. 195/75R15 carries 2.