Tire Size Box

285/60R18 vs 285/65R18

285/65R18 compared with 285/60R18

+3.6% diameter, 0.0" width

285/65R18 is 32.59" tall vs 31.46". More than the 3% rule of thumb, so check carefully before switching.

31.5"18" rim6.7"11.2" wide
285/60R18 (solid) compared with 285/65R18 (dashed outline), drawn to scale

With 285/65R18 tires, when your speedometer says 60 mph you are really going

62.1 mph

285/65R18 is +1.12 inches (+3.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/60R18285/65R18Difference%
Overall diameter31.46"32.59"+1.12"+3.6%
Section width11.22"11.22"0.00"0.0%
Sidewall height6.73"7.29"+0.56"+8.3%
Circumference98.85"102.37"+3.53"+3.6%
Revolutions per mile641.0618.9−22.1−3.4%

Speedometer difference

If your vehicle came with 285/60R18 and you fit 285/65R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.1 mph+1.1 mph
40 mph41.4 mph+1.4 mph
50 mph51.8 mph+1.8 mph
60 mph62.1 mph+2.1 mph
65 mph67.3 mph+2.3 mph
70 mph72.5 mph+2.5 mph
75 mph77.7 mph+2.7 mph
80 mph82.9 mph+2.9 mph

Each size on its own

Questions

Which is bigger, 285/60R18 or 285/65R18?
285/65R18 is taller by 1.12 inches (32.59" vs 31.46"). 285/60R18 is the same width.
Can I replace 285/60R18 with 285/65R18?
It is not recommended without checking carefully. The diameter difference is +3.6%, 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 285/65R18 change my speedometer?
When your speedometer reads 60 mph with 285/65R18 fitted (calibrated for 285/60R18), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.6%.
Will 285/65R18 lift my vehicle?
Ride height changes by half the diameter difference: +0.56 inches of ground clearance at the axle.

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