215/75R16 vs 205/80R16
Going from one to the other changes the overall height by +0.8 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/75R16 | 205/80R16 | Change |
|---|---|---|---|
| Overall height | 28.7" | 28.9" | +0.8 % |
| Sidewall | 6.35" | 6.46" | +1.7 % |
| Section width | 215 mm | 205 mm | -4.7 % |
| Circumference | 90.2" | 90.8" | +0.8 % |
| Revs per mile | 703 | 698 | -0.8 % |
| Axle height | 14.35" | 14.46" | +2.8 mm |
| Approved rim width | 6–8" | 5.5–7.5" | 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 215/75R16. Fit 205/80R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.2 mph | +0.2 |
| 50 mph | 50.4 mph | +0.4 |
| 70 mph | 70.5 mph | +0.5 |
| 90 mph | 90.7 mph | +0.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,075 on the road, so it under-counts by 75. At a true 70 mph the first turns 820 times a minute, the second 814.
What drivers reported
215/75R16 carries 11 complaints. Nobody has filed one naming 205/80R16.