ElpiAuto265/75R17 vs 315/70R17
315/70R17 is 1.71″ (44 mm) taller than 265/75R17, a 5.2% difference in overall diameter — outside the ±3% band, so expect the speedometer to drift and check for rubbing before fitting.
| Measurement | 265/75R17 | 315/70R17 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 32.65″ | 34.36″ | +1.71″ | +5.2% |
| Section width | 10.43″ | 12.40″ | +1.97″ | +18.9% |
| Sidewall height | 7.82″ | 8.68″ | +0.86″ | +10.9% |
| Circumference | 102.57″ | 107.95″ | +5.38″ | +5.2% |
| Revs per mile | 617.7 | 586.9 | −30.8 | −5.0% |
| Revs per km | 383.8 | 364.7 | −19.1 | −5.0% |
Speedometer: with 265/75R17 as the original, 315/70R17 makes an indicated 60 mph really about 63.1 mph, and the axle sits ~0.86″ higher.
Reading this comparison
The overall diameter is what matters here: 315/70R17 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.