Tire Size Box

185/70R13 vs 185/75R13

185/75R13 compared with 185/70R13

+3.1% diameter, 0.0" width

185/75R13 is 23.93" tall vs 23.20". More than the 3% rule of thumb, so check carefully before switching.

23.2"13" rim5.1"7.3" wide
185/70R13 (solid) compared with 185/75R13 (dashed outline), drawn to scale

With 185/75R13 tires, when your speedometer says 60 mph you are really going

61.9 mph

185/75R13 is +0.73 inches (+3.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/70R13185/75R13Difference%
Overall diameter23.20"23.93"+0.73"+3.1%
Section width7.28"7.28"0.00"0.0%
Sidewall height5.10"5.46"+0.36"+7.1%
Circumference72.88"75.16"+2.29"+3.1%
Revolutions per mile869.4843.0−26.5−3.0%

Speedometer difference

If your vehicle came with 185/70R13 and you fit 185/75R13, 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 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph61.9 mph+1.9 mph
65 mph67.0 mph+2.0 mph
70 mph72.2 mph+2.2 mph
75 mph77.4 mph+2.4 mph
80 mph82.5 mph+2.5 mph

Each size on its own

Questions

Which is bigger, 185/70R13 or 185/75R13?
185/75R13 is taller by 0.73 inches (23.93" vs 23.20"). 185/70R13 is the same width.
Can I replace 185/70R13 with 185/75R13?
It is not recommended without checking carefully. The diameter difference is +3.1%, 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 185/75R13 change my speedometer?
When your speedometer reads 60 mph with 185/75R13 fitted (calibrated for 185/70R13), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.1%.
Will 185/75R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.36 inches of ground clearance at the axle.

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