Tire Size Box

185/80R13 vs 205/80R13

205/80R13 compared with 185/80R13

+5.1% diameter, +0.8" width

205/80R13 is 25.91" tall vs 24.65". More than the 3% rule of thumb, so check carefully before switching.

24.7"13" rim5.8"7.3" wide
185/80R13 (solid) compared with 205/80R13 (dashed outline), drawn to scale

With 205/80R13 tires, when your speedometer says 60 mph you are really going

63.1 mph

205/80R13 is +1.26 inches (+5.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/80R13205/80R13Difference%
Overall diameter24.65"25.91"+1.26"+5.1%
Section width7.28"8.07"+0.79"+10.8%
Sidewall height5.83"6.46"+0.63"+10.8%
Circumference77.45"81.41"+3.96"+5.1%
Revolutions per mile818.1778.3−39.8−4.9%

Speedometer difference

If your vehicle came with 185/80R13 and you fit 205/80R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.0 mph+1.0 mph
30 mph31.5 mph+1.5 mph
40 mph42.0 mph+2.0 mph
50 mph52.6 mph+2.6 mph
60 mph63.1 mph+3.1 mph
65 mph68.3 mph+3.3 mph
70 mph73.6 mph+3.6 mph
75 mph78.8 mph+3.8 mph
80 mph84.1 mph+4.1 mph

Each size on its own

Questions

Which is bigger, 185/80R13 or 205/80R13?
205/80R13 is taller by 1.26 inches (25.91" vs 24.65"). 205/80R13 is wider by 0.79 inches.
Can I replace 185/80R13 with 205/80R13?
It is not recommended without checking carefully. The diameter difference is +5.1%, 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 205/80R13 change my speedometer?
When your speedometer reads 60 mph with 205/80R13 fitted (calibrated for 185/80R13), your real speed is 63.1 mph. Your odometer will under-count miles by about 5.1%.
Will 205/80R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.63 inches of ground clearance at the axle.

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