Tire Size Box

205/75R13 vs 205/85R13

205/85R13 compared with 205/75R13

+6.4% diameter, 0.0" width

205/85R13 is 26.72" tall vs 25.11". More than the 3% rule of thumb, so check carefully before switching.

25.1"13" rim6.1"8.1" wide
205/75R13 (solid) compared with 205/85R13 (dashed outline), drawn to scale

With 205/85R13 tires, when your speedometer says 60 mph you are really going

63.9 mph

205/85R13 is +1.61 inches (+6.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/75R13205/85R13Difference%
Overall diameter25.11"26.72"+1.61"+6.4%
Section width8.07"8.07"0.00"0.0%
Sidewall height6.05"6.86"+0.81"+13.3%
Circumference78.87"83.94"+5.07"+6.4%
Revolutions per mile803.3754.8−48.5−6.0%

Speedometer difference

If your vehicle came with 205/75R13 and you fit 205/85R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph31.9 mph+1.9 mph
40 mph42.6 mph+2.6 mph
50 mph53.2 mph+3.2 mph
60 mph63.9 mph+3.9 mph
65 mph69.2 mph+4.2 mph
70 mph74.5 mph+4.5 mph
75 mph79.8 mph+4.8 mph
80 mph85.1 mph+5.1 mph

Each size on its own

Questions

Which is bigger, 205/75R13 or 205/85R13?
205/85R13 is taller by 1.61 inches (26.72" vs 25.11"). 205/75R13 is the same width.
Can I replace 205/75R13 with 205/85R13?
It is not recommended without checking carefully. The diameter difference is +6.4%, 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 205/85R13 change my speedometer?
When your speedometer reads 60 mph with 205/85R13 fitted (calibrated for 205/75R13), your real speed is 63.9 mph. Your odometer will under-count miles by about 6.4%.
Will 205/85R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.81 inches of ground clearance at the axle.

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