Tire Size Box

175/60R15 vs 175/70R15

175/70R15 compared with 175/60R15

+5.9% diameter, 0.0" width

175/70R15 is 24.65" tall vs 23.27". More than the 3% rule of thumb, so check carefully before switching.

23.3"15" rim4.1"6.9" wide
175/60R15 (solid) compared with 175/70R15 (dashed outline), drawn to scale

With 175/70R15 tires, when your speedometer says 60 mph you are really going

63.6 mph

175/70R15 is +1.38 inches (+5.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

175/60R15175/70R15Difference%
Overall diameter23.27"24.65"+1.38"+5.9%
Section width6.89"6.89"0.00"0.0%
Sidewall height4.13"4.82"+0.69"+16.7%
Circumference73.10"77.43"+4.33"+5.9%
Revolutions per mile866.8818.3−48.5−5.6%

Speedometer difference

If your vehicle came with 175/60R15 and you fit 175/70R15, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.2 mph+1.2 mph
30 mph31.8 mph+1.8 mph
40 mph42.4 mph+2.4 mph
50 mph53.0 mph+3.0 mph
60 mph63.6 mph+3.6 mph
65 mph68.8 mph+3.8 mph
70 mph74.1 mph+4.1 mph
75 mph79.4 mph+4.4 mph
80 mph84.7 mph+4.7 mph

Each size on its own

Questions

Which is bigger, 175/60R15 or 175/70R15?
175/70R15 is taller by 1.38 inches (24.65" vs 23.27"). 175/60R15 is the same width.
Can I replace 175/60R15 with 175/70R15?
It is not recommended without checking carefully. The diameter difference is +5.9%, 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 175/70R15 change my speedometer?
When your speedometer reads 60 mph with 175/70R15 fitted (calibrated for 175/60R15), your real speed is 63.6 mph. Your odometer will under-count miles by about 5.9%.
Will 175/70R15 lift my vehicle?
Ride height changes by half the diameter difference: +0.69 inches of ground clearance at the axle.

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