ElpiAuto265/70R17 vs 37X12.50R17
37X12.50R17 is 5.39″ (137 mm) taller than 265/70R17, a 17.1% difference in overall diameter — outside the ±3% band, so expect the speedometer to drift and check for rubbing before fitting.
The sidewall heights are very different — ride and steering feel will change noticeably even though the diameter is close.
| Measurement | 265/70R17 | 37X12.50R17 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 31.61″ | 37.00″ | +5.39″ | +17.1% |
| Section width | 10.43″ | 12.50″ | +2.07″ | +19.8% |
| Sidewall height | 7.30″ | 10.00″ | +2.70″ | +36.9% |
| Circumference | 99.29″ | 116.24″ | +16.94″ | +17.1% |
| Revs per mile | 638.1 | 545.1 | −93.0 | −14.6% |
| Revs per km | 396.5 | 338.7 | −57.8 | −14.6% |
Speedometer: with 265/70R17 as the original, 37X12.50R17 makes an indicated 60 mph really about 70.2 mph, and the axle sits ~2.70″ higher.
Reading this comparison
The overall diameter is what matters here: 37X12.50R17 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.