285/65R17 vs 275/70R17

275/70R17 is 0.57 in (14.5 mm) taller than 285/65R17, a +1.81% diameter difference. With the speedometer set for 285/65R17, an indicated 60 mph is 61.1 mph on 275/70R17.

Is this a safe swap?

Diameter difference +1.81%: within the ±3% guideline

By overall diameter alone, 275/70R17 falls inside the ±3% range commonly used as a guideline when replacing 285/65R17. 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.

285/65R17 vs 275/70R17 differences
Measurement	285/65R17	275/70R17	Difference	% diff
Overall diameter	31.59 in (802.3 mm)	32.16 in (816.8 mm)	+0.57 in (+14.5 mm)	+1.81%
Sidewall height	7.29 in (185.3 mm)	7.58 in (192.5 mm)	+0.29 in (+7.3 mm)	+3.91%
Section width	11.22 in (285.0 mm)	10.83 in (275.0 mm)	−0.39 in (−10.0 mm)	−3.51%
Circumference	99.23 in (2,520.5 mm)	101.03 in (2,566.1 mm)	+1.79 in (+45.6 mm)	+1.81%
Revolutions per mile	639	627	−11	−1.78%

True speed with the speedometer calibrated for 285/65R17
Indicated	Actual on 285/65R17	Actual on 275/70R17	Difference
30 mph	30.0 mph	30.5 mph	+0.5 mph
60 mph	60.0 mph	61.1 mph	+1.1 mph
75 mph	75.0 mph	76.4 mph	+1.4 mph

Ride-height change: 275/70R17 raises the vehicle by 0.29 in (7.3 mm) at the axle (half the +14.5 mm diameter difference).

275/70R17 is 0.57 in taller than 285/65R17 and 10 mm narrower, a 1.81% difference in overall diameter.

With the speedometer calibrated for 285/65R17, an indicated 60 mph is actually 61.1 mph on 275/70R17, and revolutions per mile change from 639 to 627.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 285/65R17

Other comparisons with 275/70R17

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