Tire Size Box

235/25R22 vs 235/30R22

235/30R22 compared with 235/25R22

+3.5% diameter, 0.0" width

235/30R22 is 27.55" tall vs 26.63". More than the 3% rule of thumb, so check carefully before switching.

26.6"22" rim2.3"9.3" wide
235/25R22 (solid) compared with 235/30R22 (dashed outline), drawn to scale

With 235/30R22 tires, when your speedometer says 60 mph you are really going

62.1 mph

235/30R22 is +0.93 inches (+3.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

235/25R22235/30R22Difference%
Overall diameter26.63"27.55"+0.93"+3.5%
Section width9.25"9.25"0.00"0.0%
Sidewall height2.31"2.78"+0.46"+20.0%
Circumference83.65"86.55"+2.91"+3.5%
Revolutions per mile757.5732.0−25.4−3.4%

Speedometer difference

If your vehicle came with 235/25R22 and you fit 235/30R22, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.4 mph+1.4 mph
50 mph51.7 mph+1.7 mph
60 mph62.1 mph+2.1 mph
65 mph67.3 mph+2.3 mph
70 mph72.4 mph+2.4 mph
75 mph77.6 mph+2.6 mph
80 mph82.8 mph+2.8 mph

Each size on its own

Questions

Which is bigger, 235/25R22 or 235/30R22?
235/30R22 is taller by 0.93 inches (27.55" vs 26.63"). 235/25R22 is the same width.
Can I replace 235/25R22 with 235/30R22?
It is not recommended without checking carefully. The diameter difference is +3.5%, 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 235/30R22 change my speedometer?
When your speedometer reads 60 mph with 235/30R22 fitted (calibrated for 235/25R22), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.5%.
Will 235/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.46 inches of ground clearance at the axle.

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