ElpiAuto265/75R17 vs 37X12.50R17
37X12.50R17 is 4.35″ (110 mm) taller than 265/75R17, a 13.3% 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 | 265/75R17 | 37X12.50R17 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 32.65″ | 37.00″ | +4.35″ | +13.3% |
| Section width | 10.43″ | 12.50″ | +2.07″ | +19.8% |
| Sidewall height | 7.82″ | 10.00″ | +2.18″ | +27.8% |
| Circumference | 102.57″ | 116.24″ | +13.67″ | +13.3% |
| Revs per mile | 617.7 | 545.1 | −72.6 | −11.8% |
| Revs per km | 383.8 | 338.7 | −45.1 | −11.8% |
Speedometer: with 265/75R17 as the original, 37X12.50R17 makes an indicated 60 mph really about 68.0 mph, and the axle sits ~2.18″ 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.