235/70R16 vs 245/70R16
Going from one to the other changes the overall height by +1.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 235/70R16 | 245/70R16 | Change |
|---|---|---|---|
| Overall height | 29.0" | 29.5" | +1.9 % |
| Sidewall | 6.48" | 6.75" | +4.3 % |
| Section width | 235 mm | 245 mm | +4.3 % |
| Circumference | 91.0" | 92.7" | +1.9 % |
| Revs per mile | 697 | 684 | -1.9 % |
| Axle height | 14.48" | 14.75" | +7.0 mm |
| Approved rim width | 6.5–8.5" | 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 235/70R16. Fit 245/70R16 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.6 mph | +0.6 |
| 50 mph | 51.0 mph | +1.0 |
| 70 mph | 71.3 mph | +1.3 |
| 90 mph | 91.7 mph | +1.7 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,190 on the road, so it under-counts by 190. At a true 70 mph the first turns 813 times a minute, the second 798.
What drivers reported
235/70R16 carries 139 complaints. 245/70R16 carries 74 and 2 deaths.