Tire Size Box

155/70R14 vs 175/70R14

175/70R14 compared with 155/70R14

+4.9% diameter, +0.8" width

175/70R14 is 23.65" tall vs 22.54". More than the 3% rule of thumb, so check carefully before switching.

22.5"14" rim4.3"6.1" wide
155/70R14 (solid) compared with 175/70R14 (dashed outline), drawn to scale

With 175/70R14 tires, when your speedometer says 60 mph you are really going

62.9 mph

175/70R14 is +1.10 inches (+4.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

155/70R14175/70R14Difference%
Overall diameter22.54"23.65"+1.10"+4.9%
Section width6.10"6.89"+0.79"+12.9%
Sidewall height4.27"4.82"+0.55"+12.9%
Circumference70.82"74.29"+3.46"+4.9%
Revolutions per mile894.6852.9−41.7−4.7%

Speedometer difference

If your vehicle came with 155/70R14 and you fit 175/70R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.0 mph+1.0 mph
30 mph31.5 mph+1.5 mph
40 mph42.0 mph+2.0 mph
50 mph52.4 mph+2.4 mph
60 mph62.9 mph+2.9 mph
65 mph68.2 mph+3.2 mph
70 mph73.4 mph+3.4 mph
75 mph78.7 mph+3.7 mph
80 mph83.9 mph+3.9 mph

Each size on its own

Questions

Which is bigger, 155/70R14 or 175/70R14?
175/70R14 is taller by 1.10 inches (23.65" vs 22.54"). 175/70R14 is wider by 0.79 inches.
Can I replace 155/70R14 with 175/70R14?
It is not recommended without checking carefully. The diameter difference is +4.9%, 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 175/70R14 change my speedometer?
When your speedometer reads 60 mph with 175/70R14 fitted (calibrated for 155/70R14), your real speed is 62.9 mph. Your odometer will under-count miles by about 4.9%.
Will 175/70R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.55 inches of ground clearance at the axle.

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