245/70R19 vs 235/75R19
Going from one to the other changes the overall height by +1.2 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 245/70R19 | 235/75R19 | Change |
|---|---|---|---|
| Overall height | 32.5" | 32.9" | +1.2 % |
| Sidewall | 6.75" | 6.94" | +2.8 % |
| Section width | 245 mm | 235 mm | -4.1 % |
| Circumference | 102.1" | 103.3" | +1.2 % |
| Revs per mile | 620 | 613 | -1.2 % |
| Axle height | 16.25" | 16.44" | +4.8 mm |
| Approved rim width | 7–9" | 6.5–8.5" | 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 245/70R19. Fit 235/75R19 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.6 mph | +0.6 |
| 70 mph | 70.8 mph | +0.8 |
| 90 mph | 91.0 mph | +1.0 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,115 on the road, so it under-counts by 115. At a true 70 mph the first turns 724 times a minute, the second 716.
What drivers reported
245/70R19 carries 3 complaints. Nobody has filed one naming 235/75R19.