TireSizesFinder

265/40R17 vs 265/30R19

265/30R19 is 0.09 in (2.2 mm) shorter than 265/40R17, a −0.34% diameter difference. With the speedometer set for 265/40R17, an indicated 60 mph is 59.8 mph on 265/30R19.

Is this a safe swap?

Diameter difference −0.34%: under 1%

By overall diameter alone, 265/30R19 is a near match for 265/40R17; 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: 265/40R17 (25.35 in) vs 265/30R19 (25.26 in)265/40R1725.35 in × 10.43 in265/30R1925.26 in × 10.43 in
Side profile and tread width, drawn to the same scale.
265/40R17 vs 265/30R19 differences
Measurement265/40R17265/30R19Difference% diff
Overall diameter25.35 in (643.8 mm)25.26 in (641.6 mm)−0.09 in (−2.2 mm)−0.34%
Sidewall height4.17 in (106.0 mm)3.13 in (79.5 mm)−1.04 in (−26.5 mm)−25.00%
Section width10.43 in (265.0 mm)10.43 in (265.0 mm)0.00 in (0.0 mm)0.00%
Circumference79.63 in (2,022.6 mm)79.36 in (2,015.6 mm)−0.27 in (−6.9 mm)−0.34%
Revolutions per mile796798+3+0.34%
True speed with the speedometer calibrated for 265/40R17
IndicatedActual on 265/40R17Actual on 265/30R19Difference
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: 265/30R19 lowers the vehicle by 0.04 in (1.1 mm) at the axle (half the −2.2 mm diameter difference).

265/30R19 is 0.09 in shorter than 265/40R17 and the same width, a 0.34% difference in overall diameter.

With the speedometer calibrated for 265/40R17, an indicated 60 mph is actually 59.8 mph on 265/30R19, and revolutions per mile change from 796 to 798.

265/30R19 mounts on a 19-inch wheel, a plus-2 fitment from the 17-inch wheel of 265/40R17.

Size pages

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