Tire Size Box

165/70R13 vs 185/70R13

185/70R13 compared with 165/70R13

+5.0% diameter, +0.8" width

185/70R13 is 23.20" tall vs 22.09". More than the 3% rule of thumb, so check carefully before switching.

22.1"13" rim4.5"6.5" wide
165/70R13 (solid) compared with 185/70R13 (dashed outline), drawn to scale

With 185/70R13 tires, when your speedometer says 60 mph you are really going

63.0 mph

185/70R13 is +1.10 inches (+5.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

165/70R13185/70R13Difference%
Overall diameter22.09"23.20"+1.10"+5.0%
Section width6.50"7.28"+0.79"+12.1%
Sidewall height4.55"5.10"+0.55"+12.1%
Circumference69.41"72.88"+3.46"+5.0%
Revolutions per mile912.8869.4−43.4−4.8%

Speedometer difference

If your vehicle came with 165/70R13 and you fit 185/70R13, 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 mph84.0 mph+4.0 mph

Each size on its own

Questions

Which is bigger, 165/70R13 or 185/70R13?
185/70R13 is taller by 1.10 inches (23.20" vs 22.09"). 185/70R13 is wider by 0.79 inches.
Can I replace 165/70R13 with 185/70R13?
It is not recommended without checking carefully. The diameter difference is +5.0%, 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 185/70R13 change my speedometer?
When your speedometer reads 60 mph with 185/70R13 fitted (calibrated for 165/70R13), your real speed is 63.0 mph. Your odometer will under-count miles by about 5.0%.
Will 185/70R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.55 inches of ground clearance at the axle.

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