Tire Size Box

285/35R19 vs 275/40R19

275/40R19 compared with 285/35R19

+3.0% diameter, −0.4" width

275/40R19 is 27.66" tall vs 26.85". More than the 3% rule of thumb, so check carefully before switching.

26.9"19" rim3.9"11.2" wide
285/35R19 (solid) compared with 275/40R19 (dashed outline), drawn to scale

With 275/40R19 tires, when your speedometer says 60 mph you are really going

61.8 mph

275/40R19 is +0.81 inches (+3.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

285/35R19275/40R19Difference%
Overall diameter26.85"27.66"+0.81"+3.0%
Section width11.22"10.83"−0.39"−3.5%
Sidewall height3.93"4.33"+0.40"+10.3%
Circumference84.37"86.90"+2.54"+3.0%
Revolutions per mile751.0729.1−21.9−2.9%

Speedometer difference

If your vehicle came with 285/35R19 and you fit 275/40R19, 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 mph51.5 mph+1.5 mph
60 mph61.8 mph+1.8 mph
65 mph67.0 mph+2.0 mph
70 mph72.1 mph+2.1 mph
75 mph77.3 mph+2.3 mph
80 mph82.4 mph+2.4 mph

Each size on its own

Questions

Which is bigger, 285/35R19 or 275/40R19?
275/40R19 is taller by 0.81 inches (27.66" vs 26.85"). 285/35R19 is wider by 0.39 inches.
Can I replace 285/35R19 with 275/40R19?
It is not recommended without checking carefully. The diameter difference is +3.0%, 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 275/40R19 change my speedometer?
When your speedometer reads 60 mph with 275/40R19 fitted (calibrated for 285/35R19), your real speed is 61.8 mph. Your odometer will under-count miles by about 3.0%.
Will 275/40R19 lift my vehicle?
Ride height changes by half the diameter difference: +0.40 inches of ground clearance at the axle.

Other comparisons