Tire Size Box

305/25R22 vs 295/30R22

295/30R22 compared with 305/25R22

+3.4% diameter, −0.4" width

295/30R22 is 28.97" tall vs 28.00". More than the 3% rule of thumb, so check carefully before switching.

28.0"22" rim3.0"12.0" wide
305/25R22 (solid) compared with 295/30R22 (dashed outline), drawn to scale

With 295/30R22 tires, when your speedometer says 60 mph you are really going

62.1 mph

295/30R22 is +0.96 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

305/25R22295/30R22Difference%
Overall diameter28.00"28.97"+0.96"+3.4%
Section width12.01"11.61"−0.39"−3.3%
Sidewall height3.00"3.48"+0.48"+16.1%
Circumference87.98"91.01"+3.03"+3.4%
Revolutions per mile720.2696.2−24.0−3.3%

Speedometer difference

If your vehicle came with 305/25R22 and you fit 295/30R22, 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 mph67.2 mph+2.2 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, 305/25R22 or 295/30R22?
295/30R22 is taller by 0.96 inches (28.97" vs 28.00"). 305/25R22 is wider by 0.39 inches.
Can I replace 305/25R22 with 295/30R22?
It is not recommended without checking carefully. The diameter difference is +3.4%, 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 295/30R22 change my speedometer?
When your speedometer reads 60 mph with 295/30R22 fitted (calibrated for 305/25R22), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.4%.
Will 295/30R22 lift my vehicle?
Ride height changes by half the diameter difference: +0.48 inches of ground clearance at the axle.

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