215/75R17 vs 235/70R17
Going from one to the other changes the overall height by +0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/75R17 | 235/70R17 | Change |
|---|---|---|---|
| Overall height | 29.7" | 30.0" | +0.9 % |
| Sidewall | 6.35" | 6.48" | +2.0 % |
| Section width | 215 mm | 235 mm | +9.3 % |
| Circumference | 93.3" | 94.1" | +0.9 % |
| Revs per mile | 679 | 673 | -0.9 % |
| Axle height | 14.85" | 14.98" | +3.3 mm |
| Approved rim width | 6–8" | 6.5–8.5" | overlap 6.5–8" |
Both are approved on a rim 6.5" to 8" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 215/75R17. Fit 235/70R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.4 mph | +0.4 |
| 70 mph | 70.6 mph | +0.6 |
| 90 mph | 90.8 mph | +0.8 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,086 on the road, so it under-counts by 86. At a true 70 mph the first turns 792 times a minute, the second 786.
What drivers reported
Nobody has filed a complaint naming 215/75R17. 235/70R17 carries 46.