205/80R15 vs 215/80R15
Going from one to the other changes the overall height by +2.3 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 205/80R15 | 215/80R15 | Change |
|---|---|---|---|
| Overall height | 27.9" | 28.5" | +2.3 % |
| Sidewall | 6.46" | 6.77" | +4.9 % |
| Section width | 205 mm | 215 mm | +4.9 % |
| Circumference | 87.7" | 89.7" | +2.3 % |
| Revs per mile | 723 | 707 | -2.3 % |
| Axle height | 13.96" | 14.27" | +8.0 mm |
| Approved rim width | 5.5–7.5" | 6–8" | overlap 6–7.5" |
Both are approved on a rim 6" to 7.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 205/80R15. Fit 215/80R15 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.7 mph | +0.7 |
| 50 mph | 51.1 mph | +1.1 |
| 70 mph | 71.6 mph | +1.6 |
| 90 mph | 92.0 mph | +2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,226 on the road, so it under-counts by 226. At a true 70 mph the first turns 843 times a minute, the second 824.