195/40R15 vs 215/40R15
Going from one to the other changes the overall height by +3.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/40R15 | 215/40R15 | Change |
|---|---|---|---|
| Overall height | 21.1" | 21.8" | +3.0 % |
| Sidewall | 3.07" | 3.39" | +10.3 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 66.4" | 68.4" | +3.0 % |
| Revs per mile | 954 | 926 | -3.0 % |
| Axle height | 10.57" | 10.89" | +8.0 mm |
| Approved rim width | 5.5–7" | 6–8" | 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 195/40R15. Fit 215/40R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.9 mph | +0.9 |
| 50 mph | 51.5 mph | +1.5 |
| 70 mph | 72.1 mph | +2.1 |
| 90 mph | 92.7 mph | +2.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,298 on the road, so it under-counts by 298. At a true 70 mph the first turns 1113 times a minute, the second 1081.