TireSizesFinder

31x10.50R15 vs 265/70R17

265/70R17 is 0.61 in (15.4 mm) taller than 31x10.50R15, a +1.96% diameter difference. With the speedometer set for 31x10.50R15, an indicated 60 mph is 61.2 mph on 265/70R17.

Is this a safe swap?

Diameter difference +1.96%: within the ±3% guideline

By overall diameter alone, 265/70R17 falls inside the ±3% range commonly used as a guideline when replacing 31x10.50R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 31x10.50R15 (31.00 in) vs 265/70R17 (31.61 in)31x10.50R1531.00 in × 10.50 in265/70R1731.61 in × 10.43 in
Side profile and tread width, drawn to the same scale.
31x10.50R15 vs 265/70R17 differences
Measurement31x10.50R15265/70R17Difference% diff
Overall diameter31.00 in (787.4 mm)31.61 in (802.8 mm)+0.61 in (+15.4 mm)+1.96%
Sidewall height8.00 in (203.2 mm)7.30 in (185.5 mm)−0.70 in (−17.7 mm)−8.71%
Section width10.50 in (266.7 mm)10.43 in (265.0 mm)−0.07 in (−1.7 mm)−0.64%
Circumference97.39 in (2,473.7 mm)99.29 in (2,522.1 mm)+1.90 in (+48.4 mm)+1.96%
Revolutions per mile651638−12−1.92%
True speed with the speedometer calibrated for 31x10.50R15
IndicatedActual on 31x10.50R15Actual on 265/70R17Difference
30 mph30.0 mph30.6 mph+0.6 mph
60 mph60.0 mph61.2 mph+1.2 mph
75 mph75.0 mph76.5 mph+1.5 mph

Ride-height change: 265/70R17 raises the vehicle by 0.30 in (7.7 mm) at the axle (half the +15.4 mm diameter difference).

265/70R17 is 0.61 in taller than 31x10.50R15 and 2 mm narrower, a 1.96% difference in overall diameter.

With the speedometer calibrated for 31x10.50R15, an indicated 60 mph is actually 61.2 mph on 265/70R17, and revolutions per mile change from 651 to 638.

265/70R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 31x10.50R15.

Size pages

Other comparisons with 31x10.50R15

Other comparisons with 265/70R17

Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.