TireSizesFinder

265/65R18 vs 285/65R18

285/65R18 is 1.02 in (26.0 mm) taller than 265/65R18, a +3.24% diameter difference. With the speedometer set for 265/65R18, an indicated 60 mph is 61.9 mph on 285/65R18.

Is this a safe swap?

Diameter difference +3.24%: outside the ±3% guideline

By overall diameter alone, 285/65R18 falls outside the ±3% range commonly used as a guideline when replacing 265/65R18; speedometer and ride-height changes are larger. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 265/65R18 (31.56 in) vs 285/65R18 (32.59 in)265/65R1831.56 in × 10.43 in285/65R1832.59 in × 11.22 in
Side profile and tread width, drawn to the same scale.
265/65R18 vs 285/65R18 differences
Measurement265/65R18285/65R18Difference% diff
Overall diameter31.56 in (801.7 mm)32.59 in (827.7 mm)+1.02 in (+26.0 mm)+3.24%
Sidewall height6.78 in (172.3 mm)7.29 in (185.3 mm)+0.51 in (+13.0 mm)+7.55%
Section width10.43 in (265.0 mm)11.22 in (285.0 mm)+0.79 in (+20.0 mm)+7.55%
Circumference99.16 in (2,518.6 mm)102.37 in (2,600.3 mm)+3.22 in (+81.7 mm)+3.24%
Revolutions per mile639619−20−3.14%
True speed with the speedometer calibrated for 265/65R18
IndicatedActual on 265/65R18Actual on 285/65R18Difference
30 mph30.0 mph31.0 mph+1.0 mph
60 mph60.0 mph61.9 mph+1.9 mph
75 mph75.0 mph77.4 mph+2.4 mph

Ride-height change: 285/65R18 raises the vehicle by 0.51 in (13.0 mm) at the axle (half the +26.0 mm diameter difference).

285/65R18 is 1.02 in taller than 265/65R18 and 20 mm wider, a 3.24% difference in overall diameter.

With the speedometer calibrated for 265/65R18, an indicated 60 mph is actually 61.9 mph on 285/65R18, and revolutions per mile change from 639 to 619.

Both sizes mount on 18-inch wheels.

Size pages

Other comparisons with 265/65R18

Other comparisons with 285/65R18

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