Tire Size Box

185/75R13 vs 205/75R13

205/75R13 compared with 185/75R13

+4.9% diameter, +0.8" width

205/75R13 is 25.11" tall vs 23.93". More than the 3% rule of thumb, so check carefully before switching.

23.9"13" rim5.5"7.3" wide
185/75R13 (solid) compared with 205/75R13 (dashed outline), drawn to scale

With 205/75R13 tires, when your speedometer says 60 mph you are really going

63.0 mph

205/75R13 is +1.18 inches (+4.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/75R13205/75R13Difference%
Overall diameter23.93"25.11"+1.18"+4.9%
Section width7.28"8.07"+0.79"+10.8%
Sidewall height5.46"6.05"+0.59"+10.8%
Circumference75.16"78.87"+3.71"+4.9%
Revolutions per mile843.0803.3−39.7−4.7%

Speedometer difference

If your vehicle came with 185/75R13 and you fit 205/75R13, 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 mph52.5 mph+2.5 mph
60 mph63.0 mph+3.0 mph
65 mph68.2 mph+3.2 mph
70 mph73.5 mph+3.5 mph
75 mph78.7 mph+3.7 mph
80 mph83.9 mph+3.9 mph

Each size on its own

Questions

Which is bigger, 185/75R13 or 205/75R13?
205/75R13 is taller by 1.18 inches (25.11" vs 23.93"). 205/75R13 is wider by 0.79 inches.
Can I replace 185/75R13 with 205/75R13?
It is not recommended without checking carefully. The diameter difference is +4.9%, 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 205/75R13 change my speedometer?
When your speedometer reads 60 mph with 205/75R13 fitted (calibrated for 185/75R13), your real speed is 63.0 mph. Your odometer will under-count miles by about 4.9%.
Will 205/75R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

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