Tire Size Box

145/80R13 vs 145/85R13

145/85R13 compared with 145/80R13

+2.6% diameter, 0.0" width

145/85R13 is 22.70" tall vs 22.13". Within the 3% rule, so usually interchangeable.

22.1"13" rim4.6"5.7" wide
145/80R13 (solid) compared with 145/85R13 (dashed outline), drawn to scale

With 145/85R13 tires, when your speedometer says 60 mph you are really going

61.5 mph

145/85R13 is +0.57 inches (+2.6%) in overall diameter. That is within the 3% most shops and makers allow.

145/80R13145/85R13Difference%
Overall diameter22.13"22.70"+0.57"+2.6%
Section width5.71"5.71"0.00"0.0%
Sidewall height4.57"4.85"+0.29"+6.3%
Circumference69.54"71.33"+1.79"+2.6%
Revolutions per mile911.2888.3−22.9−2.5%

Speedometer difference

If your vehicle came with 145/80R13 and you fit 145/85R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.5 mph+0.5 mph
30 mph30.8 mph+0.8 mph
40 mph41.0 mph+1.0 mph
50 mph51.3 mph+1.3 mph
60 mph61.5 mph+1.5 mph
65 mph66.7 mph+1.7 mph
70 mph71.8 mph+1.8 mph
75 mph76.9 mph+1.9 mph
80 mph82.1 mph+2.1 mph

Each size on its own

Questions

Which is bigger, 145/80R13 or 145/85R13?
145/85R13 is taller by 0.57 inches (22.70" vs 22.13"). 145/80R13 is the same width.
Can I replace 145/80R13 with 145/85R13?
Usually, yes. The diameter difference is +2.6%, inside the 3% rule of thumb most tire shops use. Check that the wider or taller tire clears your suspension and fenders, and that its load index meets your placard.
How much will 145/85R13 change my speedometer?
When your speedometer reads 60 mph with 145/85R13 fitted (calibrated for 145/80R13), your real speed is 61.5 mph. Your odometer will under-count miles by about 2.6%.
Will 145/85R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.29 inches of ground clearance at the axle.

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