Tire Size Box

295/25R24 vs 285/30R24

285/30R24 compared with 295/25R24

+3.1% diameter, −0.4" width

285/30R24 is 30.73" tall vs 29.81". More than the 3% rule of thumb, so check carefully before switching.

29.8"24" rim2.9"11.6" wide
295/25R24 (solid) compared with 285/30R24 (dashed outline), drawn to scale

With 285/30R24 tires, when your speedometer says 60 mph you are really going

61.9 mph

285/30R24 is +0.93 inches (+3.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

295/25R24285/30R24Difference%
Overall diameter29.81"30.73"+0.93"+3.1%
Section width11.61"11.22"−0.39"−3.4%
Sidewall height2.90"3.37"+0.46"+15.9%
Circumference93.64"96.55"+2.91"+3.1%
Revolutions per mile676.6656.3−20.4−3.0%

Speedometer difference

If your vehicle came with 295/25R24 and you fit 285/30R24, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph30.9 mph+0.9 mph
40 mph41.2 mph+1.2 mph
50 mph51.6 mph+1.6 mph
60 mph61.9 mph+1.9 mph
65 mph67.0 mph+2.0 mph
70 mph72.2 mph+2.2 mph
75 mph77.3 mph+2.3 mph
80 mph82.5 mph+2.5 mph

Each size on its own

Questions

Which is bigger, 295/25R24 or 285/30R24?
285/30R24 is taller by 0.93 inches (30.73" vs 29.81"). 295/25R24 is wider by 0.39 inches.
Can I replace 295/25R24 with 285/30R24?
It is not recommended without checking carefully. The diameter difference is +3.1%, 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 285/30R24 change my speedometer?
When your speedometer reads 60 mph with 285/30R24 fitted (calibrated for 295/25R24), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.1%.
Will 285/30R24 lift my vehicle?
Ride height changes by half the diameter difference: +0.46 inches of ground clearance at the axle.

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