TireSizesFinder

235/85R16 vs 245/75R17

245/75R17 is 0.26 in (6.6 mm) shorter than 235/85R16, a −0.82% diameter difference. With the speedometer set for 235/85R16, an indicated 60 mph is 59.5 mph on 245/75R17.

Is this a safe swap?

Diameter difference −0.82%: under 1%

By overall diameter alone, 245/75R17 is a near match for 235/85R16; 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: 235/85R16 (31.73 in) vs 245/75R17 (31.47 in)235/85R1631.73 in × 9.25 in245/75R1731.47 in × 9.65 in
Side profile and tread width, drawn to the same scale.
235/85R16 vs 245/75R17 differences
Measurement235/85R16245/75R17Difference% diff
Overall diameter31.73 in (805.9 mm)31.47 in (799.3 mm)−0.26 in (−6.6 mm)−0.82%
Sidewall height7.86 in (199.8 mm)7.23 in (183.8 mm)−0.63 in (−16.0 mm)−8.01%
Section width9.25 in (235.0 mm)9.65 in (245.0 mm)+0.39 in (+10.0 mm)+4.26%
Circumference99.68 in (2,531.8 mm)98.86 in (2,511.1 mm)−0.82 in (−20.7 mm)−0.82%
Revolutions per mile636641+5+0.83%
True speed with the speedometer calibrated for 235/85R16
IndicatedActual on 235/85R16Actual on 245/75R17Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.5 mph−0.5 mph
75 mph75.0 mph74.4 mph−0.6 mph

Ride-height change: 245/75R17 lowers the vehicle by 0.13 in (3.3 mm) at the axle (half the −6.6 mm diameter difference).

245/75R17 is 0.26 in shorter than 235/85R16 and 10 mm wider, a 0.82% difference in overall diameter.

With the speedometer calibrated for 235/85R16, an indicated 60 mph is actually 59.5 mph on 245/75R17, and revolutions per mile change from 636 to 641.

245/75R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 235/85R16.

Size pages

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