Tire Size Box

205/25R19 vs 205/30R19

205/30R19 compared with 205/25R19

+3.5% diameter, 0.0" width

205/30R19 is 23.84" tall vs 23.04". More than the 3% rule of thumb, so check carefully before switching.

23.0"19" rim2.0"8.1" wide
205/25R19 (solid) compared with 205/30R19 (dashed outline), drawn to scale

With 205/30R19 tires, when your speedometer says 60 mph you are really going

62.1 mph

205/30R19 is +0.81 inches (+3.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/25R19205/30R19Difference%
Overall diameter23.04"23.84"+0.81"+3.5%
Section width8.07"8.07"0.00"0.0%
Sidewall height2.02"2.42"+0.40"+20.0%
Circumference72.37"74.90"+2.54"+3.5%
Revolutions per mile875.5845.9−29.6−3.4%

Speedometer difference

If your vehicle came with 205/25R19 and you fit 205/30R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.1 mph+1.1 mph
40 mph41.4 mph+1.4 mph
50 mph51.8 mph+1.8 mph
60 mph62.1 mph+2.1 mph
65 mph67.3 mph+2.3 mph
70 mph72.5 mph+2.5 mph
75 mph77.6 mph+2.6 mph
80 mph82.8 mph+2.8 mph

Each size on its own

Questions

Which is bigger, 205/25R19 or 205/30R19?
205/30R19 is taller by 0.81 inches (23.84" vs 23.04"). 205/25R19 is the same width.
Can I replace 205/25R19 with 205/30R19?
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 205/30R19 change my speedometer?
When your speedometer reads 60 mph with 205/30R19 fitted (calibrated for 205/25R19), your real speed is 62.1 mph. Your odometer will under-count miles by about 3.5%.
Will 205/30R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.40 inches of ground clearance at the axle.

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