Tire Size Box

285/50R20 vs 285/60R20

285/60R20 compared with 285/50R20

+7.2% diameter, 0.0" width

285/60R20 is 33.46" tall vs 31.22". More than the 3% rule of thumb, so check carefully before switching.

31.2"20" rim5.6"11.2" wide
285/50R20 (solid) compared with 285/60R20 (dashed outline), drawn to scale

With 285/60R20 tires, when your speedometer says 60 mph you are really going

64.3 mph

285/60R20 is +2.24 inches (+7.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/50R20285/60R20Difference%
Overall diameter31.22"33.46"+2.24"+7.2%
Section width11.22"11.22"0.00"0.0%
Sidewall height5.61"6.73"+1.12"+20.0%
Circumference98.08"105.13"+7.05"+7.2%
Revolutions per mile646.0602.7−43.3−6.7%

Speedometer difference

If your vehicle came with 285/50R20 and you fit 285/60R20, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.4 mph+1.4 mph
30 mph32.2 mph+2.2 mph
40 mph42.9 mph+2.9 mph
50 mph53.6 mph+3.6 mph
60 mph64.3 mph+4.3 mph
65 mph69.7 mph+4.7 mph
70 mph75.0 mph+5.0 mph
75 mph80.4 mph+5.4 mph
80 mph85.8 mph+5.8 mph

Each size on its own

Questions

Which is bigger, 285/50R20 or 285/60R20?
285/60R20 is taller by 2.24 inches (33.46" vs 31.22"). 285/50R20 is the same width.
Can I replace 285/50R20 with 285/60R20?
It is not recommended without checking carefully. The diameter difference is +7.2%, 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 285/60R20 change my speedometer?
When your speedometer reads 60 mph with 285/60R20 fitted (calibrated for 285/50R20), your real speed is 64.3 mph. Your odometer will under-count miles by about 7.2%.
Will 285/60R20 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

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