Tire Size Box

185/85R16 vs 205/85R16

205/85R16 compared with 185/85R16

+4.7% diameter, +0.8" width

205/85R16 is 29.72" tall vs 28.38". More than the 3% rule of thumb, so check carefully before switching.

28.4"16" rim6.2"7.3" wide
185/85R16 (solid) compared with 205/85R16 (dashed outline), drawn to scale

With 205/85R16 tires, when your speedometer says 60 mph you are really going

62.8 mph

205/85R16 is +1.34 inches (+4.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/85R16205/85R16Difference%
Overall diameter28.38"29.72"+1.34"+4.7%
Section width7.28"8.07"+0.79"+10.8%
Sidewall height6.19"6.86"+0.67"+10.8%
Circumference89.16"93.37"+4.21"+4.7%
Revolutions per mile710.6678.6−32.0−4.5%

Speedometer difference

If your vehicle came with 185/85R16 and you fit 205/85R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.4 mph+1.4 mph
40 mph41.9 mph+1.9 mph
50 mph52.4 mph+2.4 mph
60 mph62.8 mph+2.8 mph
65 mph68.1 mph+3.1 mph
70 mph73.3 mph+3.3 mph
75 mph78.5 mph+3.5 mph
80 mph83.8 mph+3.8 mph

Each size on its own

Questions

Which is bigger, 185/85R16 or 205/85R16?
205/85R16 is taller by 1.34 inches (29.72" vs 28.38"). 205/85R16 is wider by 0.79 inches.
Can I replace 185/85R16 with 205/85R16?
It is not recommended without checking carefully. The diameter difference is +4.7%, 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 205/85R16 change my speedometer?
When your speedometer reads 60 mph with 205/85R16 fitted (calibrated for 185/85R16), your real speed is 62.8 mph. Your odometer will under-count miles by about 4.7%.
Will 205/85R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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