Tire Size Box

305/30R19 vs 305/35R19

305/35R19 compared with 305/30R19

+4.6% diameter, 0.0" width

305/35R19 is 27.41" tall vs 26.20". More than the 3% rule of thumb, so check carefully before switching.

26.2"19" rim3.6"12.0" wide
305/30R19 (solid) compared with 305/35R19 (dashed outline), drawn to scale

With 305/35R19 tires, when your speedometer says 60 mph you are really going

62.7 mph

305/35R19 is +1.20 inches (+4.6%) in overall diameter. That is more than the 3% most shops and makers recommend.

305/30R19305/35R19Difference%
Overall diameter26.20"27.41"+1.20"+4.6%
Section width12.01"12.01"0.00"0.0%
Sidewall height3.60"4.20"+0.60"+16.7%
Circumference82.32"86.10"+3.77"+4.6%
Revolutions per mile769.6735.9−33.7−4.4%

Speedometer difference

If your vehicle came with 305/30R19 and you fit 305/35R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.9 mph+0.9 mph
30 mph31.4 mph+1.4 mph
40 mph41.8 mph+1.8 mph
50 mph52.3 mph+2.3 mph
60 mph62.7 mph+2.7 mph
65 mph68.0 mph+3.0 mph
70 mph73.2 mph+3.2 mph
75 mph78.4 mph+3.4 mph
80 mph83.7 mph+3.7 mph

Each size on its own

Questions

Which is bigger, 305/30R19 or 305/35R19?
305/35R19 is taller by 1.20 inches (27.41" vs 26.20"). 305/30R19 is the same width.
Can I replace 305/30R19 with 305/35R19?
It is not recommended without checking carefully. The diameter difference is +4.6%, 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 305/35R19 change my speedometer?
When your speedometer reads 60 mph with 305/35R19 fitted (calibrated for 305/30R19), your real speed is 62.7 mph. Your odometer will under-count miles by about 4.6%.
Will 305/35R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.60 inches of ground clearance at the axle.

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