215/40R17 vs 195/45R17
Going from one to the other changes the overall height by +0.6 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/40R17 | 195/45R17 | Change |
|---|---|---|---|
| Overall height | 23.8" | 23.9" | +0.6 % |
| Sidewall | 3.39" | 3.45" | +2.0 % |
| Section width | 215 mm | 195 mm | -9.3 % |
| Circumference | 74.7" | 75.1" | +0.6 % |
| Revs per mile | 848 | 844 | -0.6 % |
| Axle height | 11.89" | 11.95" | +1.8 mm |
| Approved rim width | 6–8" | 5.5–7" | overlap 6–7" |
Both are approved on a rim 6" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 215/40R17. Fit 195/45R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.2 mph | +0.2 |
| 50 mph | 50.3 mph | +0.3 |
| 70 mph | 70.4 mph | +0.4 |
| 90 mph | 90.5 mph | +0.5 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,058 on the road, so it under-counts by 58. At a true 70 mph the first turns 990 times a minute, the second 984.
What drivers reported
215/40R17 carries 2 complaints. Nobody has filed one naming 195/45R17.