Tire Size Box

165/75R13 vs 165/85R13

165/85R13 compared with 165/75R13

+5.7% diameter, 0.0" width

165/85R13 is 24.04" tall vs 22.74". More than the 3% rule of thumb, so check carefully before switching.

22.7"13" rim4.9"6.5" wide
165/75R13 (solid) compared with 165/85R13 (dashed outline), drawn to scale

With 165/85R13 tires, when your speedometer says 60 mph you are really going

63.4 mph

165/85R13 is +1.30 inches (+5.7%) in overall diameter. That is more than the 3% most shops and makers recommend.

165/75R13165/85R13Difference%
Overall diameter22.74"24.04"+1.30"+5.7%
Section width6.50"6.50"0.00"0.0%
Sidewall height4.87"5.52"+0.65"+13.3%
Circumference71.45"75.53"+4.08"+5.7%
Revolutions per mile886.7838.8−47.9−5.4%

Speedometer difference

If your vehicle came with 165/75R13 and you fit 165/85R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.1 mph+1.1 mph
30 mph31.7 mph+1.7 mph
40 mph42.3 mph+2.3 mph
50 mph52.9 mph+2.9 mph
60 mph63.4 mph+3.4 mph
65 mph68.7 mph+3.7 mph
70 mph74.0 mph+4.0 mph
75 mph79.3 mph+4.3 mph
80 mph84.6 mph+4.6 mph

Each size on its own

Questions

Which is bigger, 165/75R13 or 165/85R13?
165/85R13 is taller by 1.30 inches (24.04" vs 22.74"). 165/75R13 is the same width.
Can I replace 165/75R13 with 165/85R13?
It is not recommended without checking carefully. The diameter difference is +5.7%, 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 165/85R13 change my speedometer?
When your speedometer reads 60 mph with 165/85R13 fitted (calibrated for 165/75R13), your real speed is 63.4 mph. Your odometer will under-count miles by about 5.7%.
Will 165/85R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.65 inches of ground clearance at the axle.

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