Tire Size Box

165/75R14 vs 165/85R14

165/85R14 compared with 165/75R14

+5.5% diameter, 0.0" width

165/85R14 is 25.04" tall vs 23.74". More than the 3% rule of thumb, so check carefully before switching.

23.7"14" rim4.9"6.5" wide
165/75R14 (solid) compared with 165/85R14 (dashed outline), drawn to scale

With 165/85R14 tires, when your speedometer says 60 mph you are really going

63.3 mph

165/85R14 is +1.30 inches (+5.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

165/75R14165/85R14Difference%
Overall diameter23.74"25.04"+1.30"+5.5%
Section width6.50"6.50"0.00"0.0%
Sidewall height4.87"5.52"+0.65"+13.3%
Circumference74.59"78.68"+4.08"+5.5%
Revolutions per mile849.4805.3−44.1−5.2%

Speedometer difference

If your vehicle came with 165/75R14 and you fit 165/85R14, 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 mph63.3 mph+3.3 mph
65 mph68.6 mph+3.6 mph
70 mph73.8 mph+3.8 mph
75 mph79.1 mph+4.1 mph
80 mph84.4 mph+4.4 mph

Each size on its own

Questions

Which is bigger, 165/75R14 or 165/85R14?
165/85R14 is taller by 1.30 inches (25.04" vs 23.74"). 165/75R14 is the same width.
Can I replace 165/75R14 with 165/85R14?
It is not recommended without checking carefully. The diameter difference is +5.5%, 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 165/85R14 change my speedometer?
When your speedometer reads 60 mph with 165/85R14 fitted (calibrated for 165/75R14), your real speed is 63.3 mph. Your odometer will under-count miles by about 5.5%.
Will 165/85R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.65 inches of ground clearance at the axle.

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