215/75R16 vs 225/75R16
Going from one to the other changes the overall height by +2.1 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/75R16 | 225/75R16 | Change |
|---|---|---|---|
| Overall height | 28.7" | 29.3" | +2.1 % |
| Sidewall | 6.35" | 6.64" | +4.7 % |
| Section width | 215 mm | 225 mm | +4.7 % |
| Circumference | 90.2" | 92.0" | +2.1 % |
| Revs per mile | 703 | 689 | -2.1 % |
| Axle height | 14.35" | 14.64" | +7.5 mm |
| Approved rim width | 6–8" | 6–8.5" | 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 215/75R16. Fit 225/75R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.4 mph | +1.4 |
| 90 mph | 91.9 mph | +1.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,206 on the road, so it under-counts by 206. At a true 70 mph the first turns 820 times a minute, the second 803.