Tire Size Box

165/85R14 vs 185/85R14

185/85R14 compared with 165/85R14

+5.3% diameter, +0.8" width

185/85R14 is 26.38" tall vs 25.04". More than the 3% rule of thumb, so check carefully before switching.

25.0"14" rim5.5"6.5" wide
165/85R14 (solid) compared with 185/85R14 (dashed outline), drawn to scale

With 185/85R14 tires, when your speedometer says 60 mph you are really going

63.2 mph

185/85R14 is +1.34 inches (+5.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

165/85R14185/85R14Difference%
Overall diameter25.04"26.38"+1.34"+5.3%
Section width6.50"7.28"+0.79"+12.1%
Sidewall height5.52"6.19"+0.67"+12.1%
Circumference78.68"82.88"+4.21"+5.3%
Revolutions per mile805.3764.5−40.9−5.1%

Speedometer difference

If your vehicle came with 165/85R14 and you fit 185/85R14, 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 mph42.1 mph+2.1 mph
50 mph52.7 mph+2.7 mph
60 mph63.2 mph+3.2 mph
65 mph68.5 mph+3.5 mph
70 mph73.7 mph+3.7 mph
75 mph79.0 mph+4.0 mph
80 mph84.3 mph+4.3 mph

Each size on its own

Questions

Which is bigger, 165/85R14 or 185/85R14?
185/85R14 is taller by 1.34 inches (26.38" vs 25.04"). 185/85R14 is wider by 0.79 inches.
Can I replace 165/85R14 with 185/85R14?
It is not recommended without checking carefully. The diameter difference is +5.3%, 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 185/85R14 change my speedometer?
When your speedometer reads 60 mph with 185/85R14 fitted (calibrated for 165/85R14), your real speed is 63.2 mph. Your odometer will under-count miles by about 5.3%.
Will 185/85R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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