Tire Size Box

185/75R13 vs 185/80R13

185/80R13 compared with 185/75R13

+3.0% diameter, 0.0" width

185/80R13 is 24.65" 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 185/80R13 (dashed outline), drawn to scale

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

61.8 mph

185/80R13 is +0.73 inches (+3.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/75R13185/80R13Difference%
Overall diameter23.93"24.65"+0.73"+3.0%
Section width7.28"7.28"0.00"0.0%
Sidewall height5.46"5.83"+0.36"+6.7%
Circumference75.16"77.45"+2.29"+3.0%
Revolutions per mile843.0818.1−24.9−3.0%

Speedometer difference

If your vehicle came with 185/75R13 and you fit 185/80R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph30.9 mph+0.9 mph
40 mph41.2 mph+1.2 mph
50 mph51.5 mph+1.5 mph
60 mph61.8 mph+1.8 mph
65 mph67.0 mph+2.0 mph
70 mph72.1 mph+2.1 mph
75 mph77.3 mph+2.3 mph
80 mph82.4 mph+2.4 mph

Each size on its own

Questions

Which is bigger, 185/75R13 or 185/80R13?
185/80R13 is taller by 0.73 inches (24.65" vs 23.93"). 185/75R13 is the same width.
Can I replace 185/75R13 with 185/80R13?
It is not recommended without checking carefully. The diameter difference is +3.0%, 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 185/80R13 change my speedometer?
When your speedometer reads 60 mph with 185/80R13 fitted (calibrated for 185/75R13), your real speed is 61.8 mph. Your odometer will under-count miles by about 3.0%.
Will 185/80R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.36 inches of ground clearance at the axle.

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