Tire Size Box

255/75R16 vs 275/75R16

275/75R16 compared with 255/75R16

+3.8% diameter, +0.8" width

275/75R16 is 32.24" tall vs 31.06". More than the 3% rule of thumb, so check carefully before switching.

31.1"16" rim7.5"10.0" wide
255/75R16 (solid) compared with 275/75R16 (dashed outline), drawn to scale

With 275/75R16 tires, when your speedometer says 60 mph you are really going

62.3 mph

275/75R16 is +1.18 inches (+3.8%) in overall diameter. That is more than the 3% most shops and makers recommend.

255/75R16275/75R16Difference%
Overall diameter31.06"32.24"+1.18"+3.8%
Section width10.04"10.83"+0.79"+7.8%
Sidewall height7.53"8.12"+0.59"+7.8%
Circumference97.57"101.29"+3.71"+3.8%
Revolutions per mile649.3625.6−23.8−3.7%

Speedometer difference

If your vehicle came with 255/75R16 and you fit 275/75R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.8 mph+0.8 mph
30 mph31.1 mph+1.1 mph
40 mph41.5 mph+1.5 mph
50 mph51.9 mph+1.9 mph
60 mph62.3 mph+2.3 mph
65 mph67.5 mph+2.5 mph
70 mph72.7 mph+2.7 mph
75 mph77.9 mph+2.9 mph
80 mph83.0 mph+3.0 mph

Each size on its own

Questions

Which is bigger, 255/75R16 or 275/75R16?
275/75R16 is taller by 1.18 inches (32.24" vs 31.06"). 275/75R16 is wider by 0.79 inches.
Can I replace 255/75R16 with 275/75R16?
It is not recommended without checking carefully. The diameter difference is +3.8%, 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 275/75R16 change my speedometer?
When your speedometer reads 60 mph with 275/75R16 fitted (calibrated for 255/75R16), your real speed is 62.3 mph. Your odometer will under-count miles by about 3.8%.
Will 275/75R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.59 inches of ground clearance at the axle.

Other comparisons