Tire Size Box

285/50R18 vs 285/60R18

285/60R18 compared with 285/50R18

+7.7% diameter, 0.0" width

285/60R18 is 31.46" tall vs 29.22". More than the 3% rule of thumb, so check carefully before switching.

29.2"18" rim5.6"11.2" wide
285/50R18 (solid) compared with 285/60R18 (dashed outline), drawn to scale

With 285/60R18 tires, when your speedometer says 60 mph you are really going

64.6 mph

285/60R18 is +2.24 inches (+7.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/50R18285/60R18Difference%
Overall diameter29.22"31.46"+2.24"+7.7%
Section width11.22"11.22"0.00"0.0%
Sidewall height5.61"6.73"+1.12"+20.0%
Circumference91.80"98.85"+7.05"+7.7%
Revolutions per mile690.2641.0−49.2−7.1%

Speedometer difference

If your vehicle came with 285/50R18 and you fit 285/60R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.5 mph+1.5 mph
30 mph32.3 mph+2.3 mph
40 mph43.1 mph+3.1 mph
50 mph53.8 mph+3.8 mph
60 mph64.6 mph+4.6 mph
65 mph70.0 mph+5.0 mph
70 mph75.4 mph+5.4 mph
75 mph80.8 mph+5.8 mph
80 mph86.1 mph+6.1 mph

Each size on its own

Questions

Which is bigger, 285/50R18 or 285/60R18?
285/60R18 is taller by 2.24 inches (31.46" vs 29.22"). 285/50R18 is the same width.
Can I replace 285/50R18 with 285/60R18?
It is not recommended without checking carefully. The diameter difference is +7.7%, 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 285/60R18 change my speedometer?
When your speedometer reads 60 mph with 285/60R18 fitted (calibrated for 285/50R18), your real speed is 64.6 mph. Your odometer will under-count miles by about 7.7%.
Will 285/60R18 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

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