TireSizesFinder

195/70R15 vs 275/40R17

275/40R17 is 0.09 in (2.2 mm) shorter than 195/70R15, a −0.34% diameter difference. With the speedometer set for 195/70R15, an indicated 60 mph is 59.8 mph on 275/40R17.

Is this a safe swap?

Diameter difference −0.34%: under 1%

By overall diameter alone, 275/40R17 is a near match for 195/70R15; 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: 195/70R15 (25.75 in) vs 275/40R17 (25.66 in)195/70R1525.75 in × 7.68 in275/40R1725.66 in × 10.83 in
Side profile and tread width, drawn to the same scale.
195/70R15 vs 275/40R17 differences
Measurement195/70R15275/40R17Difference% diff
Overall diameter25.75 in (654.0 mm)25.66 in (651.8 mm)−0.09 in (−2.2 mm)−0.34%
Sidewall height5.37 in (136.5 mm)4.33 in (110.0 mm)−1.04 in (−26.5 mm)−19.41%
Section width7.68 in (195.0 mm)10.83 in (275.0 mm)+3.15 in (+80.0 mm)+41.03%
Circumference80.89 in (2,054.6 mm)80.62 in (2,047.7 mm)−0.27 in (−6.9 mm)−0.34%
Revolutions per mile783786+3+0.34%
True speed with the speedometer calibrated for 195/70R15
IndicatedActual on 195/70R15Actual on 275/40R17Difference
30 mph30.0 mph29.9 mph−0.1 mph
60 mph60.0 mph59.8 mph−0.2 mph
75 mph75.0 mph74.7 mph−0.3 mph

Ride-height change: 275/40R17 lowers the vehicle by 0.04 in (1.1 mm) at the axle (half the −2.2 mm diameter difference).

275/40R17 is 0.09 in shorter than 195/70R15 and 80 mm wider, a 0.34% difference in overall diameter.

With the speedometer calibrated for 195/70R15, an indicated 60 mph is actually 59.8 mph on 275/40R17, and revolutions per mile change from 783 to 786.

275/40R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 195/70R15.

Size pages

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