225/75R16 vs 215/80R16
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 | 225/75R16 | 215/80R16 | Change |
|---|---|---|---|
| Overall height | 29.3" | 29.5" | +0.9 % |
| Sidewall | 6.64" | 6.77" | +1.9 % |
| Section width | 225 mm | 215 mm | -4.4 % |
| Circumference | 92.0" | 92.8" | +0.9 % |
| Revs per mile | 689 | 683 | -0.9 % |
| Axle height | 14.64" | 14.77" | +3.3 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 225/75R16. Fit 215/80R16 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 10,087 on the road, so it under-counts by 87. At a true 70 mph the first turns 803 times a minute, the second 796.
What drivers reported
225/75R16 carries 121 complaints. Nobody has filed one naming 215/80R16.