175/85R15 vs 195/75R15
Going from one to the other changes the overall height by -0.7 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 175/85R15 | 195/75R15 | Change |
|---|---|---|---|
| Overall height | 26.7" | 26.5" | -0.7 % |
| Sidewall | 5.86" | 5.76" | -1.7 % |
| Section width | 175 mm | 195 mm | +11.4 % |
| Circumference | 83.9" | 83.3" | -0.7 % |
| Revs per mile | 755 | 761 | +0.7 % |
| Axle height | 13.36" | 13.26" | -2.5 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 175/85R15. Fit 195/75R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.8 mph | -0.2 |
| 50 mph | 49.6 mph | -0.4 |
| 70 mph | 69.5 mph | -0.5 |
| 90 mph | 89.3 mph | -0.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,926 on the road, so it over-counts by 74. At a true 70 mph the first turns 881 times a minute, the second 887.
What drivers reported
Nobody has filed a complaint naming 175/85R15. 195/75R15 carries 2.