275/70R17 vs 285/70R17

285/70R17 is 0.55 in (14.0 mm) taller than 275/70R17, a +1.71% diameter difference. With the speedometer set for 275/70R17, an indicated 60 mph is 61.0 mph on 285/70R17.

Is this a safe swap?

Diameter difference +1.71%: within the ±3% guideline

By overall diameter alone, 285/70R17 falls inside the ±3% range commonly used as a guideline when replacing 275/70R17. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

275/70R17 vs 285/70R17 differences
Measurement	275/70R17	285/70R17	Difference	% diff
Overall diameter	32.16 in (816.8 mm)	32.71 in (830.8 mm)	+0.55 in (+14.0 mm)	+1.71%
Sidewall height	7.58 in (192.5 mm)	7.85 in (199.5 mm)	+0.28 in (+7.0 mm)	+3.64%
Section width	10.83 in (275.0 mm)	11.22 in (285.0 mm)	+0.39 in (+10.0 mm)	+3.64%
Circumference	101.03 in (2,566.1 mm)	102.76 in (2,610.0 mm)	+1.73 in (+44.0 mm)	+1.71%
Revolutions per mile	627	617	−11	−1.69%

True speed with the speedometer calibrated for 275/70R17
Indicated	Actual on 275/70R17	Actual on 285/70R17	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.0 mph	+1.0 mph
75 mph	75.0 mph	76.3 mph	+1.3 mph

Ride-height change: 285/70R17 raises the vehicle by 0.28 in (7.0 mm) at the axle (half the +14.0 mm diameter difference).

285/70R17 is 0.55 in taller than 275/70R17 and 10 mm wider, a 1.71% difference in overall diameter.

With the speedometer calibrated for 275/70R17, an indicated 60 mph is actually 61.0 mph on 285/70R17, and revolutions per mile change from 627 to 617.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 275/70R17

Other comparisons with 285/70R17

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.