Tire Size Box

355/25R22 vs 355/30R22

355/30R22 compared with 355/25R22

+4.8% diameter, 0.0" width

355/30R22 is 30.39" tall vs 28.99". More than the 3% rule of thumb, so check carefully before switching.

29.0"22" rim3.5"14.0" wide
355/25R22 (solid) compared with 355/30R22 (dashed outline), drawn to scale

With 355/30R22 tires, when your speedometer says 60 mph you are really going

62.9 mph

355/30R22 is +1.40 inches (+4.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

355/25R22355/30R22Difference%
Overall diameter28.99"30.39"+1.40"+4.8%
Section width13.98"13.98"0.00"0.0%
Sidewall height3.49"4.19"+0.70"+20.0%
Circumference91.07"95.46"+4.39"+4.8%
Revolutions per mile695.7663.7−32.0−4.6%

Speedometer difference

If your vehicle came with 355/25R22 and you fit 355/30R22, 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 mph73.4 mph+3.4 mph
75 mph78.6 mph+3.6 mph
80 mph83.9 mph+3.9 mph

Each size on its own

Questions

Which is bigger, 355/25R22 or 355/30R22?
355/30R22 is taller by 1.40 inches (30.39" vs 28.99"). 355/25R22 is the same width.
Can I replace 355/25R22 with 355/30R22?
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 355/30R22 change my speedometer?
When your speedometer reads 60 mph with 355/30R22 fitted (calibrated for 355/25R22), your real speed is 62.9 mph. Your odometer will under-count miles by about 4.8%.
Will 355/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.70 inches of ground clearance at the axle.

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