TireSizesFinder

285/65R17 vs 265/65R18

265/65R18 is 0.02 in (0.6 mm) shorter than 285/65R17, a −0.07% diameter difference. With the speedometer set for 285/65R17, an indicated 60 mph is 60.0 mph on 265/65R18.

Is this a safe swap?

Diameter difference −0.07%: under 1%

By overall diameter alone, 265/65R18 is a near match for 285/65R17; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 285/65R17 (31.59 in) vs 265/65R18 (31.56 in)285/65R1731.59 in × 11.22 in265/65R1831.56 in × 10.43 in
Side profile and tread width, drawn to the same scale.
285/65R17 vs 265/65R18 differences
Measurement285/65R17265/65R18Difference% diff
Overall diameter31.59 in (802.3 mm)31.56 in (801.7 mm)−0.02 in (−0.6 mm)−0.07%
Sidewall height7.29 in (185.3 mm)6.78 in (172.3 mm)−0.51 in (−13.0 mm)−7.02%
Section width11.22 in (285.0 mm)10.43 in (265.0 mm)−0.79 in (−20.0 mm)−7.02%
Circumference99.23 in (2,520.5 mm)99.16 in (2,518.6 mm)−0.07 in (−1.9 mm)−0.07%
Revolutions per mile6396390+0.07%
True speed with the speedometer calibrated for 285/65R17
IndicatedActual on 285/65R17Actual on 265/65R18Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.0 mph0.0 mph
75 mph75.0 mph74.9 mph−0.1 mph

Ride-height change: 265/65R18 lowers the vehicle by 0.01 in (0.3 mm) at the axle (half the −0.6 mm diameter difference).

265/65R18 is 0.02 in shorter than 285/65R17 and 20 mm narrower, a 0.07% difference in overall diameter.

With the speedometer calibrated for 285/65R17, an indicated 60 mph is actually 60.0 mph on 265/65R18, and revolutions per mile change from 639 to 639.

265/65R18 mounts on a 18-inch wheel, a plus-1 fitment from the 17-inch wheel of 285/65R17.

Size pages

Other comparisons with 285/65R17

Other comparisons with 265/65R18

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