225/80R16 vs 245/70R16
Going from one to the other changes the overall height by -2.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 225/80R16 | 245/70R16 | Change |
|---|---|---|---|
| Overall height | 30.2" | 29.5" | -2.2 % |
| Sidewall | 7.09" | 6.75" | -4.7 % |
| Section width | 225 mm | 245 mm | +8.9 % |
| Circumference | 94.8" | 92.7" | -2.2 % |
| Revs per mile | 668 | 684 | +2.2 % |
| Axle height | 15.09" | 14.75" | -8.5 mm |
| Approved rim width | 6–8.5" | 7–9" | overlap 7–8.5" |
Both are approved on a rim 7" to 8.5" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 225/80R16. Fit 245/70R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 29.3 mph | -0.7 |
| 50 mph | 48.9 mph | -1.1 |
| 70 mph | 68.4 mph | -1.6 |
| 90 mph | 88.0 mph | -2.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 9,778 on the road, so it over-counts by 222. At a true 70 mph the first turns 780 times a minute, the second 798.
What drivers reported
225/80R16 carries 3 complaints. 245/70R16 carries 74 and 2 deaths.