Tire Size Box

275/25R22 vs 275/30R22

275/30R22 compared with 275/25R22

+3.9% diameter, 0.0" width

275/30R22 is 28.50" tall vs 27.41". More than the 3% rule of thumb, so check carefully before switching.

27.4"22" rim2.7"10.8" wide
275/25R22 (solid) compared with 275/30R22 (dashed outline), drawn to scale

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

62.4 mph

275/30R22 is +1.08 inches (+3.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/25R22275/30R22Difference%
Overall diameter27.41"28.50"+1.08"+3.9%
Section width10.83"10.83"0.00"0.0%
Sidewall height2.71"3.25"+0.54"+20.0%
Circumference86.12"89.52"+3.40"+3.9%
Revolutions per mile735.7707.8−28.0−3.8%

Speedometer difference

If your vehicle came with 275/25R22 and you fit 275/30R22, 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 mph83.2 mph+3.2 mph

Each size on its own

Questions

Which is bigger, 275/25R22 or 275/30R22?
275/30R22 is taller by 1.08 inches (28.50" vs 27.41"). 275/25R22 is the same width.
Can I replace 275/25R22 with 275/30R22?
It is not recommended without checking carefully. The diameter difference is +3.9%, 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 275/25R22), your real speed is 62.4 mph. Your odometer will under-count miles by about 3.9%.
Will 275/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.54 inches of ground clearance at the axle.

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