Tire Size Box

265/70R18 vs 265/75R18

265/75R18 compared with 265/70R18

+3.2% diameter, 0.0" width

265/75R18 is 33.65" tall vs 32.61". More than the 3% rule of thumb, so check carefully before switching.

32.6"18" rim7.3"10.4" wide
265/70R18 (solid) compared with 265/75R18 (dashed outline), drawn to scale

With 265/75R18 tires, when your speedometer says 60 mph you are really going

61.9 mph

265/75R18 is +1.04 inches (+3.2%) in overall diameter. That is more than the 3% most shops and makers recommend.

265/70R18265/75R18Difference%
Overall diameter32.61"33.65"+1.04"+3.2%
Section width10.43"10.43"0.00"0.0%
Sidewall height7.30"7.82"+0.52"+7.1%
Circumference102.44"105.71"+3.28"+3.2%
Revolutions per mile618.5599.4−19.2−3.1%

Speedometer difference

If your vehicle came with 265/70R18 and you fit 265/75R18, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.6 mph+0.6 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph61.9 mph+1.9 mph
65 mph67.1 mph+2.1 mph
70 mph72.2 mph+2.2 mph
75 mph77.4 mph+2.4 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 265/70R18 or 265/75R18?
265/75R18 is taller by 1.04 inches (33.65" vs 32.61"). 265/70R18 is the same width.
Can I replace 265/70R18 with 265/75R18?
It is not recommended without checking carefully. The diameter difference is +3.2%, 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 265/75R18 change my speedometer?
When your speedometer reads 60 mph with 265/75R18 fitted (calibrated for 265/70R18), your real speed is 61.9 mph. Your odometer will under-count miles by about 3.2%.
Will 265/75R18 lift my vehicle?
Ride height changes by half the diameter difference: +0.52 inches of ground clearance at the axle.

Other comparisons