Tire Size Box

285/55R17 vs 285/65R17

285/65R17 compared with 285/55R17

+7.6% diameter, 0.0" width

285/65R17 is 31.59" tall vs 29.34". More than the 3% rule of thumb, so check carefully before switching.

29.3"17" rim6.2"11.2" wide
285/55R17 (solid) compared with 285/65R17 (dashed outline), drawn to scale

With 285/65R17 tires, when your speedometer says 60 mph you are really going

64.6 mph

285/65R17 is +2.24 inches (+7.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/55R17285/65R17Difference%
Overall diameter29.34"31.59"+2.24"+7.6%
Section width11.22"11.22"0.00"0.0%
Sidewall height6.17"7.29"+1.12"+18.2%
Circumference92.18"99.23"+7.05"+7.6%
Revolutions per mile687.3638.5−48.8−7.1%

Speedometer difference

If your vehicle came with 285/55R17 and you fit 285/65R17, 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 mph80.7 mph+5.7 mph
80 mph86.1 mph+6.1 mph

Each size on its own

Questions

Which is bigger, 285/55R17 or 285/65R17?
285/65R17 is taller by 2.24 inches (31.59" vs 29.34"). 285/55R17 is the same width.
Can I replace 285/55R17 with 285/65R17?
It is not recommended without checking carefully. The diameter difference is +7.6%, 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 285/65R17 change my speedometer?
When your speedometer reads 60 mph with 285/65R17 fitted (calibrated for 285/55R17), your real speed is 64.6 mph. Your odometer will under-count miles by about 7.6%.
Will 285/65R17 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

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