195/40R15 vs 215/35R15
Going from one to the other changes the overall height by -1.0 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 195/40R15 | 215/35R15 | Change |
|---|---|---|---|
| Overall height | 21.1" | 20.9" | -1.0 % |
| Sidewall | 3.07" | 2.96" | -3.5 % |
| Section width | 195 mm | 215 mm | +10.3 % |
| Circumference | 66.4" | 65.7" | -1.0 % |
| Revs per mile | 954 | 964 | +1.0 % |
| Axle height | 10.57" | 10.46" | -2.8 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 215/35R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.7 mph | -0.3 |
| 50 mph | 49.5 mph | -0.5 |
| 70 mph | 69.3 mph | -0.7 |
| 90 mph | 89.1 mph | -0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,898 on the road, so it over-counts by 102. At a true 70 mph the first turns 1113 times a minute, the second 1124.