Tire Size Box

305/25R24 vs 295/30R24

295/30R24 compared with 305/25R24

+3.2% diameter, −0.4" width

295/30R24 is 30.97" tall vs 30.00". More than the 3% rule of thumb, so check carefully before switching.

30.0"24" rim3.0"12.0" wide
305/25R24 (solid) compared with 295/30R24 (dashed outline), drawn to scale

With 295/30R24 tires, when your speedometer says 60 mph you are really going

61.9 mph

295/30R24 is +0.96 inches (+3.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

305/25R24295/30R24Difference%
Overall diameter30.00"30.97"+0.96"+3.2%
Section width12.01"11.61"−0.39"−3.3%
Sidewall height3.00"3.48"+0.48"+16.1%
Circumference94.26"97.29"+3.03"+3.2%
Revolutions per mile672.2651.2−20.9−3.1%

Speedometer difference

If your vehicle came with 305/25R24 and you fit 295/30R24, 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 mph72.3 mph+2.3 mph
75 mph77.4 mph+2.4 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 305/25R24 or 295/30R24?
295/30R24 is taller by 0.96 inches (30.97" vs 30.00"). 305/25R24 is wider by 0.39 inches.
Can I replace 305/25R24 with 295/30R24?
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 295/30R24 change my speedometer?
When your speedometer reads 60 mph with 295/30R24 fitted (calibrated for 305/25R24), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.2%.
Will 295/30R24 lift my vehicle?
Ride height changes by half the diameter difference: +0.48 inches of ground clearance at the axle.

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