Tire Size Box

185/60R15 vs 205/60R15

205/60R15 compared with 185/60R15

+4.0% diameter, +0.8" width

205/60R15 is 24.69" tall vs 23.74". More than the 3% rule of thumb, so check carefully before switching.

23.7"15" rim4.4"7.3" wide
185/60R15 (solid) compared with 205/60R15 (dashed outline), drawn to scale

With 205/60R15 tires, when your speedometer says 60 mph you are really going

62.4 mph

205/60R15 is +0.94 inches (+4.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/60R15205/60R15Difference%
Overall diameter23.74"24.69"+0.94"+4.0%
Section width7.28"8.07"+0.79"+10.8%
Sidewall height4.37"4.84"+0.47"+10.8%
Circumference74.58"77.55"+2.97"+4.0%
Revolutions per mile849.5817.0−32.5−3.8%

Speedometer difference

If your vehicle came with 185/60R15 and you fit 205/60R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.6 mph+1.6 mph
50 mph52.0 mph+2.0 mph
60 mph62.4 mph+2.4 mph
65 mph67.6 mph+2.6 mph
70 mph72.8 mph+2.8 mph
75 mph78.0 mph+3.0 mph
80 mph83.2 mph+3.2 mph

Each size on its own

Questions

Which is bigger, 185/60R15 or 205/60R15?
205/60R15 is taller by 0.94 inches (24.69" vs 23.74"). 205/60R15 is wider by 0.79 inches.
Can I replace 185/60R15 with 205/60R15?
It is not recommended without checking carefully. The diameter difference is +4.0%, 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 205/60R15 change my speedometer?
When your speedometer reads 60 mph with 205/60R15 fitted (calibrated for 185/60R15), your real speed is 62.4 mph. Your odometer will under-count miles by about 4.0%.
Will 205/60R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.47 inches of ground clearance at the axle.

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