Tire Size Box

355/30R19 vs 345/35R19

345/35R19 compared with 355/30R19

+4.1% diameter, −0.4" width

345/35R19 is 28.51" tall vs 27.39". More than the 3% rule of thumb, so check carefully before switching.

27.4"19" rim4.2"14.0" wide
355/30R19 (solid) compared with 345/35R19 (dashed outline), drawn to scale

With 345/35R19 tires, when your speedometer says 60 mph you are really going

62.5 mph

345/35R19 is +1.12 inches (+4.1%) in overall diameter. That is more than the 3% most shops and makers recommend.

355/30R19345/35R19Difference%
Overall diameter27.39"28.51"+1.12"+4.1%
Section width13.98"13.58"−0.39"−2.8%
Sidewall height4.19"4.75"+0.56"+13.4%
Circumference86.04"89.56"+3.53"+4.1%
Revolutions per mile736.4707.5−29.0−3.9%

Speedometer difference

If your vehicle came with 355/30R19 and you fit 345/35R19, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.2 mph+1.2 mph
40 mph41.6 mph+1.6 mph
50 mph52.0 mph+2.0 mph
60 mph62.5 mph+2.5 mph
65 mph67.7 mph+2.7 mph
70 mph72.9 mph+2.9 mph
75 mph78.1 mph+3.1 mph
80 mph83.3 mph+3.3 mph

Each size on its own

Questions

Which is bigger, 355/30R19 or 345/35R19?
345/35R19 is taller by 1.12 inches (28.51" vs 27.39"). 355/30R19 is wider by 0.39 inches.
Can I replace 355/30R19 with 345/35R19?
It is not recommended without checking carefully. The diameter difference is +4.1%, 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 345/35R19 change my speedometer?
When your speedometer reads 60 mph with 345/35R19 fitted (calibrated for 355/30R19), your real speed is 62.5 mph. Your odometer will under-count miles by about 4.1%.
Will 345/35R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.56 inches of ground clearance at the axle.

Other comparisons