Tire Size Box

285/80R16 vs 285/85R16

285/85R16 compared with 285/80R16

+3.3% diameter, 0.0" width

285/85R16 is 35.07" tall vs 33.95". More than the 3% rule of thumb, so check carefully before switching.

34.0"16" rim9.0"11.2" wide
285/80R16 (solid) compared with 285/85R16 (dashed outline), drawn to scale

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

62.0 mph

285/85R16 is +1.12 inches (+3.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/80R16285/85R16Difference%
Overall diameter33.95"35.07"+1.12"+3.3%
Section width11.22"11.22"0.00"0.0%
Sidewall height8.98"9.54"+0.56"+6.3%
Circumference106.67"110.19"+3.53"+3.3%
Revolutions per mile594.0575.0−19.0−3.2%

Speedometer difference

If your vehicle came with 285/80R16 and you fit 285/85R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.1 mph+2.1 mph
70 mph72.3 mph+2.3 mph
75 mph77.5 mph+2.5 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 285/80R16 or 285/85R16?
285/85R16 is taller by 1.12 inches (35.07" vs 33.95"). 285/80R16 is the same width.
Can I replace 285/80R16 with 285/85R16?
It is not recommended without checking carefully. The diameter difference is +3.3%, 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 285/80R16), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.3%.
Will 285/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.56 inches of ground clearance at the axle.

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