225/60R16 vs 205/70R16
Going from one to the other changes the overall height by +2.5 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 225/60R16 | 205/70R16 | Change |
|---|---|---|---|
| Overall height | 26.6" | 27.3" | +2.5 % |
| Sidewall | 5.31" | 5.65" | +6.3 % |
| Section width | 225 mm | 205 mm | -8.9 % |
| Circumference | 83.7" | 85.8" | +2.5 % |
| Revs per mile | 757 | 739 | -2.5 % |
| Axle height | 13.31" | 13.65" | +8.5 mm |
| Approved rim width | 6–8.5" | 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 225/60R16. Fit 205/70R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.8 mph | +0.8 |
| 50 mph | 51.3 mph | +1.3 |
| 70 mph | 71.8 mph | +1.8 |
| 90 mph | 92.3 mph | +2.3 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,251 on the road, so it under-counts by 251. At a true 70 mph the first turns 884 times a minute, the second 862.
What drivers reported
225/60R16 carries 318 complaints and 6 deaths. 205/70R16 carries 8.