TireSizesFinder

30x9.50R15 vs 275/60R17

275/60R17 is 0.01 in (0.2 mm) shorter than 30x9.50R15, a −0.03% diameter difference. With the speedometer set for 30x9.50R15, an indicated 60 mph is 60.0 mph on 275/60R17.

Is this a safe swap?

Diameter difference −0.03%: under 1%

By overall diameter alone, 275/60R17 is a near match for 30x9.50R15; 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: 30x9.50R15 (30.00 in) vs 275/60R17 (29.99 in)30x9.50R1530.00 in × 9.50 in275/60R1729.99 in × 10.83 in
Side profile and tread width, drawn to the same scale.
30x9.50R15 vs 275/60R17 differences
Measurement30x9.50R15275/60R17Difference% diff
Overall diameter30.00 in (762.0 mm)29.99 in (761.8 mm)−0.01 in (−0.2 mm)−0.03%
Sidewall height7.50 in (190.5 mm)6.50 in (165.0 mm)−1.00 in (−25.5 mm)−13.39%
Section width9.50 in (241.3 mm)10.83 in (275.0 mm)+1.33 in (+33.7 mm)+13.97%
Circumference94.25 in (2,393.9 mm)94.22 in (2,393.3 mm)−0.02 in (−0.6 mm)−0.03%
Revolutions per mile6726720+0.03%
True speed with the speedometer calibrated for 30x9.50R15
IndicatedActual on 30x9.50R15Actual on 275/60R17Difference
30 mph30.0 mph30.0 mph0.0 mph
60 mph60.0 mph60.0 mph0.0 mph
75 mph75.0 mph75.0 mph0.0 mph

Ride-height change: 275/60R17 lowers the vehicle by 0.00 in (0.1 mm) at the axle (half the −0.2 mm diameter difference).

275/60R17 is 0.01 in shorter than 30x9.50R15 and 34 mm wider, a 0.03% difference in overall diameter.

With the speedometer calibrated for 30x9.50R15, an indicated 60 mph is actually 60.0 mph on 275/60R17, and revolutions per mile change from 672 to 672.

275/60R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 30x9.50R15.

Size pages

Other comparisons with 30x9.50R15

Other comparisons with 275/60R17

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