Tire Size Box

285/40R19 vs 285/50R19

285/50R19 compared with 285/40R19

+8.0% diameter, 0.0" width

285/50R19 is 30.22" tall vs 27.98". More than the 3% rule of thumb, so check carefully before switching.

28.0"19" rim4.5"11.2" wide
285/40R19 (solid) compared with 285/50R19 (dashed outline), drawn to scale

With 285/50R19 tires, when your speedometer says 60 mph you are really going

64.8 mph

285/50R19 is +2.24 inches (+8.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/40R19285/50R19Difference%
Overall diameter27.98"30.22"+2.24"+8.0%
Section width11.22"11.22"0.00"0.0%
Sidewall height4.49"5.61"+1.12"+25.0%
Circumference87.89"94.94"+7.05"+8.0%
Revolutions per mile720.9667.4−53.5−7.4%

Speedometer difference

If your vehicle came with 285/40R19 and you fit 285/50R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.6 mph+1.6 mph
30 mph32.4 mph+2.4 mph
40 mph43.2 mph+3.2 mph
50 mph54.0 mph+4.0 mph
60 mph64.8 mph+4.8 mph
65 mph70.2 mph+5.2 mph
70 mph75.6 mph+5.6 mph
75 mph81.0 mph+6.0 mph
80 mph86.4 mph+6.4 mph

Each size on its own

Questions

Which is bigger, 285/40R19 or 285/50R19?
285/50R19 is taller by 2.24 inches (30.22" vs 27.98"). 285/40R19 is the same width.
Can I replace 285/40R19 with 285/50R19?
It is not recommended without checking carefully. The diameter difference is +8.0%, more than the 3% most shops and makers allow. It will throw off the speedometer and may affect ABS, stability control and clearance.
How much will 285/50R19 change my speedometer?
When your speedometer reads 60 mph with 285/50R19 fitted (calibrated for 285/40R19), your real speed is 64.8 mph. Your odometer will under-count miles by about 8.0%.
Will 285/50R19 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

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