Tire Size Box

185/80R16 vs 205/80R16

205/80R16 compared with 185/80R16

+4.6% diameter, +0.8" width

205/80R16 is 28.91" tall vs 27.65". More than the 3% rule of thumb, so check carefully before switching.

27.7"16" rim5.8"7.3" wide
185/80R16 (solid) compared with 205/80R16 (dashed outline), drawn to scale

With 205/80R16 tires, when your speedometer says 60 mph you are really going

62.7 mph

205/80R16 is +1.26 inches (+4.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/80R16205/80R16Difference%
Overall diameter27.65"28.91"+1.26"+4.6%
Section width7.28"8.07"+0.79"+10.8%
Sidewall height5.83"6.46"+0.63"+10.8%
Circumference86.88"90.83"+3.96"+4.6%
Revolutions per mile729.3697.5−31.8−4.4%

Speedometer difference

If your vehicle came with 185/80R16 and you fit 205/80R16, 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 mph41.8 mph+1.8 mph
50 mph52.3 mph+2.3 mph
60 mph62.7 mph+2.7 mph
65 mph68.0 mph+3.0 mph
70 mph73.2 mph+3.2 mph
75 mph78.4 mph+3.4 mph
80 mph83.6 mph+3.6 mph

Each size on its own

Questions

Which is bigger, 185/80R16 or 205/80R16?
205/80R16 is taller by 1.26 inches (28.91" vs 27.65"). 205/80R16 is wider by 0.79 inches.
Can I replace 185/80R16 with 205/80R16?
It is not recommended without checking carefully. The diameter difference is +4.6%, 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 205/80R16 change my speedometer?
When your speedometer reads 60 mph with 205/80R16 fitted (calibrated for 185/80R16), your real speed is 62.7 mph. Your odometer will under-count miles by about 4.6%.
Will 205/80R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.63 inches of ground clearance at the axle.

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