Tire Size Box

175/75R14 vs 175/85R14

175/85R14 compared with 175/75R14

+5.7% diameter, 0.0" width

175/85R14 is 25.71" tall vs 24.33". More than the 3% rule of thumb, so check carefully before switching.

24.3"14" rim5.2"6.9" wide
175/75R14 (solid) compared with 175/85R14 (dashed outline), drawn to scale

With 175/85R14 tires, when your speedometer says 60 mph you are really going

63.4 mph

175/85R14 is +1.38 inches (+5.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

175/75R14175/85R14Difference%
Overall diameter24.33"25.71"+1.38"+5.7%
Section width6.89"6.89"0.00"0.0%
Sidewall height5.17"5.86"+0.69"+13.3%
Circumference76.45"80.78"+4.33"+5.7%
Revolutions per mile828.8784.4−44.4−5.4%

Speedometer difference

If your vehicle came with 175/75R14 and you fit 175/85R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.1 mph+1.1 mph
30 mph31.7 mph+1.7 mph
40 mph42.3 mph+2.3 mph
50 mph52.8 mph+2.8 mph
60 mph63.4 mph+3.4 mph
65 mph68.7 mph+3.7 mph
70 mph74.0 mph+4.0 mph
75 mph79.2 mph+4.2 mph
80 mph84.5 mph+4.5 mph

Each size on its own

Questions

Which is bigger, 175/75R14 or 175/85R14?
175/85R14 is taller by 1.38 inches (25.71" vs 24.33"). 175/75R14 is the same width.
Can I replace 175/75R14 with 175/85R14?
It is not recommended without checking carefully. The diameter difference is +5.7%, 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 175/85R14 change my speedometer?
When your speedometer reads 60 mph with 175/85R14 fitted (calibrated for 175/75R14), your real speed is 63.4 mph. Your odometer will under-count miles by about 5.7%.
Will 175/85R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.69 inches of ground clearance at the axle.

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