Tire Size Box

175/75R16 vs 175/85R16

175/85R16 compared with 175/75R16

+5.2% diameter, 0.0" width

175/85R16 is 27.71" tall vs 26.33". More than the 3% rule of thumb, so check carefully before switching.

26.3"16" rim5.2"6.9" wide
175/75R16 (solid) compared with 175/85R16 (dashed outline), drawn to scale

With 175/85R16 tires, when your speedometer says 60 mph you are really going

63.1 mph

175/85R16 is +1.38 inches (+5.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

175/75R16175/85R16Difference%
Overall diameter26.33"27.71"+1.38"+5.2%
Section width6.89"6.89"0.00"0.0%
Sidewall height5.17"5.86"+0.69"+13.3%
Circumference82.73"87.06"+4.33"+5.2%
Revolutions per mile765.8727.8−38.1−5.0%

Speedometer difference

If your vehicle came with 175/75R16 and you fit 175/85R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.0 mph+1.0 mph
30 mph31.6 mph+1.6 mph
40 mph42.1 mph+2.1 mph
50 mph52.6 mph+2.6 mph
60 mph63.1 mph+3.1 mph
65 mph68.4 mph+3.4 mph
70 mph73.7 mph+3.7 mph
75 mph78.9 mph+3.9 mph
80 mph84.2 mph+4.2 mph

Each size on its own

Questions

Which is bigger, 175/75R16 or 175/85R16?
175/85R16 is taller by 1.38 inches (27.71" vs 26.33"). 175/75R16 is the same width.
Can I replace 175/75R16 with 175/85R16?
It is not recommended without checking carefully. The diameter difference is +5.2%, 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 175/85R16 change my speedometer?
When your speedometer reads 60 mph with 175/85R16 fitted (calibrated for 175/75R16), your real speed is 63.1 mph. Your odometer will under-count miles by about 5.2%.
Will 175/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.69 inches of ground clearance at the axle.

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