Tire Size Box

275/70R17 vs 275/75R17

275/75R17 compared with 275/70R17

+3.4% diameter, 0.0" width

275/75R17 is 33.24" tall vs 32.16". More than the 3% rule of thumb, so check carefully before switching.

32.2"17" rim7.6"10.8" wide
275/70R17 (solid) compared with 275/75R17 (dashed outline), drawn to scale

With 275/75R17 tires, when your speedometer says 60 mph you are really going

62.0 mph

275/75R17 is +1.08 inches (+3.4%) in overall diameter. That is more than the 3% most shops and makers recommend.

275/70R17275/75R17Difference%
Overall diameter32.16"33.24"+1.08"+3.4%
Section width10.83"10.83"0.00"0.0%
Sidewall height7.58"8.12"+0.54"+7.1%
Circumference101.03"104.43"+3.40"+3.4%
Revolutions per mile627.2606.7−20.4−3.3%

Speedometer difference

If your vehicle came with 275/70R17 and you fit 275/75R17, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.7 mph+1.7 mph
60 mph62.0 mph+2.0 mph
65 mph67.2 mph+2.2 mph
70 mph72.4 mph+2.4 mph
75 mph77.5 mph+2.5 mph
80 mph82.7 mph+2.7 mph

Each size on its own

Questions

Which is bigger, 275/70R17 or 275/75R17?
275/75R17 is taller by 1.08 inches (33.24" vs 32.16"). 275/70R17 is the same width.
Can I replace 275/70R17 with 275/75R17?
It is not recommended without checking carefully. The diameter difference is +3.4%, 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 275/75R17 change my speedometer?
When your speedometer reads 60 mph with 275/75R17 fitted (calibrated for 275/70R17), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.4%.
Will 275/75R17 lift my vehicle?
Ride height changes by half the diameter difference: +0.54 inches of ground clearance at the axle.

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