ElpiAuto265/70R18 vs 285/65R18
285/65R18 is 0.02″ (1 mm) shorter than 265/70R18, a 0.1% difference in overall diameter — comfortably inside the ±3% band most fitment guides use, so it swaps straight across for gearing and the speedometer.
| Measurement | 265/70R18 | 285/65R18 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 32.61″ | 32.59″ | −0.02″ | −0.1% |
| Section width | 10.43″ | 11.22″ | +0.79″ | +7.5% |
| Sidewall height | 7.30″ | 7.29″ | −0.01″ | −0.1% |
| Circumference | 102.44″ | 102.37″ | −0.06″ | −0.1% |
| Revs per mile | 618.5 | 618.9 | +0.4 | +0.1% |
| Revs per km | 384.3 | 384.6 | +0.2 | +0.1% |
No meaningful speedometer change between these two sizes.
Reading this comparison
The overall diameter is what matters here: 265/70R18 is the taller tire. It sets ride height, gearing and how far the tire travels per revolution — which is what the speedometer and odometer count. Width and sidewall change fit and feel (a wider tire needs a wider wheel and more clearance; a shorter sidewall sharpens steering) but not the gearing.
Figures are geometric estimates from the size codes; real moulded tires vary by brand by 1–3%. Confirm load rating, wheel width and physical clearance on your vehicle before fitting. To compare any other two sizes, use the tire size comparison tool; to decode one size and see what else fits its wheel, the tire size calculator.