Tire Size Box

185/75R16 vs 185/85R16

185/85R16 compared with 185/75R16

+5.4% diameter, 0.0" width

185/85R16 is 28.38" tall vs 26.93". More than the 3% rule of thumb, so check carefully before switching.

26.9"16" rim5.5"7.3" wide
185/75R16 (solid) compared with 185/85R16 (dashed outline), drawn to scale

With 185/85R16 tires, when your speedometer says 60 mph you are really going

63.2 mph

185/85R16 is +1.46 inches (+5.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/75R16185/85R16Difference%
Overall diameter26.93"28.38"+1.46"+5.4%
Section width7.28"7.28"0.00"0.0%
Sidewall height5.46"6.19"+0.73"+13.3%
Circumference84.59"89.16"+4.58"+5.4%
Revolutions per mile749.0710.6−38.4−5.1%

Speedometer difference

If your vehicle came with 185/75R16 and you fit 185/85R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.1 mph+1.1 mph
30 mph31.6 mph+1.6 mph
40 mph42.2 mph+2.2 mph
50 mph52.7 mph+2.7 mph
60 mph63.2 mph+3.2 mph
65 mph68.5 mph+3.5 mph
70 mph73.8 mph+3.8 mph
75 mph79.1 mph+4.1 mph
80 mph84.3 mph+4.3 mph

Each size on its own

Questions

Which is bigger, 185/75R16 or 185/85R16?
185/85R16 is taller by 1.46 inches (28.38" vs 26.93"). 185/75R16 is the same width.
Can I replace 185/75R16 with 185/85R16?
It is not recommended without checking carefully. The diameter difference is +5.4%, 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 185/85R16 change my speedometer?
When your speedometer reads 60 mph with 185/85R16 fitted (calibrated for 185/75R16), your real speed is 63.2 mph. Your odometer will under-count miles by about 5.4%.
Will 185/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.73 inches of ground clearance at the axle.

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