225/35R17 vs 215/40R17
Going from one to the other changes the overall height by +2.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 225/35R17 | 215/40R17 | Change |
|---|---|---|---|
| Overall height | 23.2" | 23.8" | +2.5 % |
| Sidewall | 3.10" | 3.39" | +9.2 % |
| Section width | 225 mm | 215 mm | -4.4 % |
| Circumference | 72.9" | 74.7" | +2.5 % |
| Revs per mile | 869 | 848 | -2.5 % |
| Axle height | 11.60" | 11.89" | +7.3 mm |
| Approved rim width | 6–8.5" | 6–8" | overlap 6–8" |
Both are approved on a rim 6" to 8" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 225/35R17. Fit 215/40R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.2 mph | +1.2 |
| 70 mph | 71.7 mph | +1.7 |
| 90 mph | 92.2 mph | +2.2 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,246 on the road, so it under-counts by 246. At a true 70 mph the first turns 1014 times a minute, the second 990.
What drivers reported
Nobody has filed a complaint naming 225/35R17. 215/40R17 carries 2.