Tire Size Box

285/25R22 vs 275/30R22

275/30R22 compared with 285/25R22

+3.2% diameter, −0.4" width

275/30R22 is 28.50" 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 275/30R22 (dashed outline), drawn to scale

With 275/30R22 tires, when your speedometer says 60 mph you are really going

61.9 mph

275/30R22 is +0.89 inches (+3.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/25R22275/30R22Difference%
Overall diameter27.61"28.50"+0.89"+3.2%
Section width11.22"10.83"−0.39"−3.5%
Sidewall height2.81"3.25"+0.44"+15.8%
Circumference86.74"89.52"+2.78"+3.2%
Revolutions per mile730.5707.8−22.7−3.1%

Speedometer difference

If your vehicle came with 285/25R22 and you fit 275/30R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph61.9 mph+1.9 mph
65 mph67.1 mph+2.1 mph
70 mph72.2 mph+2.2 mph
75 mph77.4 mph+2.4 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 285/25R22 or 275/30R22?
275/30R22 is taller by 0.89 inches (28.50" vs 27.61"). 285/25R22 is wider by 0.39 inches.
Can I replace 285/25R22 with 275/30R22?
It is not recommended without checking carefully. The diameter difference is +3.2%, 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 275/30R22 change my speedometer?
When your speedometer reads 60 mph with 275/30R22 fitted (calibrated for 285/25R22), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.2%.
Will 275/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.44 inches of ground clearance at the axle.

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