Tire Size Box

265/25R19 vs 255/30R19

255/30R19 compared with 265/25R19

+3.3% diameter, −0.4" width

255/30R19 is 25.02" tall vs 24.22". More than the 3% rule of thumb, so check carefully before switching.

24.2"19" rim2.6"10.4" wide
265/25R19 (solid) compared with 255/30R19 (dashed outline), drawn to scale

With 255/30R19 tires, when your speedometer says 60 mph you are really going

62.0 mph

255/30R19 is +0.81 inches (+3.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/25R19255/30R19Difference%
Overall diameter24.22"25.02"+0.81"+3.3%
Section width10.43"10.04"−0.39"−3.8%
Sidewall height2.61"3.01"+0.40"+15.5%
Circumference76.08"78.61"+2.54"+3.3%
Revolutions per mile832.8806.0−26.9−3.2%

Speedometer difference

If your vehicle came with 265/25R19 and you fit 255/30R19, 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 mph41.3 mph+1.3 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.3 mph+2.3 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 265/25R19 or 255/30R19?
255/30R19 is taller by 0.81 inches (25.02" vs 24.22"). 265/25R19 is wider by 0.39 inches.
Can I replace 265/25R19 with 255/30R19?
It is not recommended without checking carefully. The diameter difference is +3.3%, 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 255/30R19 change my speedometer?
When your speedometer reads 60 mph with 255/30R19 fitted (calibrated for 265/25R19), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.3%.
Will 255/30R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.40 inches of ground clearance at the axle.

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