Tire Size Box

285/25R22 vs 285/30R22

285/30R22 compared with 285/25R22

+4.1% diameter, 0.0" width

285/30R22 is 28.73" tall vs 27.61". More than the 3% rule of thumb, so check carefully before switching.

27.6"22" rim2.8"11.2" wide
285/25R22 (solid) compared with 285/30R22 (dashed outline), drawn to scale

With 285/30R22 tires, when your speedometer says 60 mph you are really going

62.4 mph

285/30R22 is +1.12 inches (+4.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/25R22285/30R22Difference%
Overall diameter27.61"28.73"+1.12"+4.1%
Section width11.22"11.22"0.00"0.0%
Sidewall height2.81"3.37"+0.56"+20.0%
Circumference86.74"90.27"+3.53"+4.1%
Revolutions per mile730.5701.9−28.5−3.9%

Speedometer difference

If your vehicle came with 285/25R22 and you fit 285/30R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.6 mph+1.6 mph
50 mph52.0 mph+2.0 mph
60 mph62.4 mph+2.4 mph
65 mph67.6 mph+2.6 mph
70 mph72.8 mph+2.8 mph
75 mph78.0 mph+3.0 mph
80 mph83.3 mph+3.3 mph

Each size on its own

Questions

Which is bigger, 285/25R22 or 285/30R22?
285/30R22 is taller by 1.12 inches (28.73" vs 27.61"). 285/25R22 is the same width.
Can I replace 285/25R22 with 285/30R22?
It is not recommended without checking carefully. The diameter difference is +4.1%, 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 285/30R22 change my speedometer?
When your speedometer reads 60 mph with 285/30R22 fitted (calibrated for 285/25R22), your real speed is 62.4 mph. Your odometer will under-count miles by about 4.1%.
Will 285/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.56 inches of ground clearance at the axle.

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