Tire Size Box

285/75R16 vs 285/85R16

285/85R16 compared with 285/75R16

+6.8% diameter, 0.0" width

285/85R16 is 35.07" tall vs 32.83". More than the 3% rule of thumb, so check carefully before switching.

32.8"16" rim8.4"11.2" wide
285/75R16 (solid) compared with 285/85R16 (dashed outline), drawn to scale

With 285/85R16 tires, when your speedometer says 60 mph you are really going

64.1 mph

285/85R16 is +2.24 inches (+6.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/75R16285/85R16Difference%
Overall diameter32.83"35.07"+2.24"+6.8%
Section width11.22"11.22"0.00"0.0%
Sidewall height8.42"9.54"+1.12"+13.3%
Circumference103.14"110.19"+7.05"+6.8%
Revolutions per mile614.3575.0−39.3−6.4%

Speedometer difference

If your vehicle came with 285/75R16 and you fit 285/85R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.4 mph+1.4 mph
30 mph32.1 mph+2.1 mph
40 mph42.7 mph+2.7 mph
50 mph53.4 mph+3.4 mph
60 mph64.1 mph+4.1 mph
65 mph69.4 mph+4.4 mph
70 mph74.8 mph+4.8 mph
75 mph80.1 mph+5.1 mph
80 mph85.5 mph+5.5 mph

Each size on its own

Questions

Which is bigger, 285/75R16 or 285/85R16?
285/85R16 is taller by 2.24 inches (35.07" vs 32.83"). 285/75R16 is the same width.
Can I replace 285/75R16 with 285/85R16?
It is not recommended without checking carefully. The diameter difference is +6.8%, 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 285/85R16 change my speedometer?
When your speedometer reads 60 mph with 285/85R16 fitted (calibrated for 285/75R16), your real speed is 64.1 mph. Your odometer will under-count miles by about 6.8%.
Will 285/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +1.12 inches of ground clearance at the axle.

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