255/80R17 vs 295/70R17

295/70R17 is 0.20 in (5.0 mm) taller than 255/80R17, a +0.60% diameter difference. With the speedometer set for 255/80R17, an indicated 60 mph is 60.4 mph on 295/70R17.

Is this a safe swap?

Diameter difference +0.60%: under 1%

By overall diameter alone, 295/70R17 is a near match for 255/80R17; the speedometer changes by less than 1%. 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.

255/80R17 vs 295/70R17 differences
Measurement	255/80R17	295/70R17	Difference	% diff
Overall diameter	33.06 in (839.8 mm)	33.26 in (844.8 mm)	+0.20 in (+5.0 mm)	+0.60%
Sidewall height	8.03 in (204.0 mm)	8.13 in (206.5 mm)	+0.10 in (+2.5 mm)	+1.23%
Section width	10.04 in (255.0 mm)	11.61 in (295.0 mm)	+1.57 in (+40.0 mm)	+15.69%
Circumference	103.87 in (2,638.3 mm)	104.49 in (2,654.0 mm)	+0.62 in (+15.7 mm)	+0.60%
Revolutions per mile	610	606	−4	−0.59%

True speed with the speedometer calibrated for 255/80R17
Indicated	Actual on 255/80R17	Actual on 295/70R17	Difference
30 mph	30.0 mph	30.2 mph	+0.2 mph
60 mph	60.0 mph	60.4 mph	+0.4 mph
75 mph	75.0 mph	75.4 mph	+0.4 mph

Ride-height change: 295/70R17 raises the vehicle by 0.10 in (2.5 mm) at the axle (half the +5.0 mm diameter difference).

295/70R17 is 0.20 in taller than 255/80R17 and 40 mm wider, a 0.60% difference in overall diameter.

With the speedometer calibrated for 255/80R17, an indicated 60 mph is actually 60.4 mph on 295/70R17, and revolutions per mile change from 610 to 606.

Both sizes mount on 17-inch wheels.

Size pages

Other comparisons with 255/80R17

Other comparisons with 295/70R17

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