Tire Size Box

165/80R13 vs 185/80R13

185/80R13 compared with 165/80R13

+5.4% diameter, +0.8" width

185/80R13 is 24.65" tall vs 23.39". More than the 3% rule of thumb, so check carefully before switching.

23.4"13" rim5.2"6.5" wide
165/80R13 (solid) compared with 185/80R13 (dashed outline), drawn to scale

With 185/80R13 tires, when your speedometer says 60 mph you are really going

63.2 mph

185/80R13 is +1.26 inches (+5.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

165/80R13185/80R13Difference%
Overall diameter23.39"24.65"+1.26"+5.4%
Section width6.50"7.28"+0.79"+12.1%
Sidewall height5.20"5.83"+0.63"+12.1%
Circumference73.49"77.45"+3.96"+5.4%
Revolutions per mile862.1818.1−44.1−5.1%

Speedometer difference

If your vehicle came with 165/80R13 and you fit 185/80R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.1 mph+1.1 mph
30 mph31.6 mph+1.6 mph
40 mph42.2 mph+2.2 mph
50 mph52.7 mph+2.7 mph
60 mph63.2 mph+3.2 mph
65 mph68.5 mph+3.5 mph
70 mph73.8 mph+3.8 mph
75 mph79.0 mph+4.0 mph
80 mph84.3 mph+4.3 mph

Each size on its own

Questions

Which is bigger, 165/80R13 or 185/80R13?
185/80R13 is taller by 1.26 inches (24.65" vs 23.39"). 185/80R13 is wider by 0.79 inches.
Can I replace 165/80R13 with 185/80R13?
It is not recommended without checking carefully. The diameter difference is +5.4%, 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 185/80R13 change my speedometer?
When your speedometer reads 60 mph with 185/80R13 fitted (calibrated for 165/80R13), your real speed is 63.2 mph. Your odometer will under-count miles by about 5.4%.
Will 185/80R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.63 inches of ground clearance at the axle.

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