Tire Size Box

225/85R13 vs 245/85R13

245/85R13 compared with 225/85R13

+4.8% diameter, +0.8" width

245/85R13 is 29.40" tall vs 28.06". More than the 3% rule of thumb, so check carefully before switching.

28.1"13" rim7.5"8.9" wide
225/85R13 (solid) compared with 245/85R13 (dashed outline), drawn to scale

With 245/85R13 tires, when your speedometer says 60 mph you are really going

62.9 mph

245/85R13 is +1.34 inches (+4.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

225/85R13245/85R13Difference%
Overall diameter28.06"29.40"+1.34"+4.8%
Section width8.86"9.65"+0.79"+8.9%
Sidewall height7.53"8.20"+0.67"+8.9%
Circumference88.15"92.36"+4.21"+4.8%
Revolutions per mile718.8686.0−32.7−4.6%

Speedometer difference

If your vehicle came with 225/85R13 and you fit 245/85R13, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.0 mph+1.0 mph
30 mph31.4 mph+1.4 mph
40 mph41.9 mph+1.9 mph
50 mph52.4 mph+2.4 mph
60 mph62.9 mph+2.9 mph
65 mph68.1 mph+3.1 mph
70 mph73.3 mph+3.3 mph
75 mph78.6 mph+3.6 mph
80 mph83.8 mph+3.8 mph

Each size on its own

Questions

Which is bigger, 225/85R13 or 245/85R13?
245/85R13 is taller by 1.34 inches (29.40" vs 28.06"). 245/85R13 is wider by 0.79 inches.
Can I replace 225/85R13 with 245/85R13?
It is not recommended without checking carefully. The diameter difference is +4.8%, 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 245/85R13 change my speedometer?
When your speedometer reads 60 mph with 245/85R13 fitted (calibrated for 225/85R13), your real speed is 62.9 mph. Your odometer will under-count miles by about 4.8%.
Will 245/85R13 lift my vehicle?
Ride height changes by half the diameter difference: +0.67 inches of ground clearance at the axle.

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