Tire Size Box

185/70R14 vs 185/80R14

185/80R14 compared with 185/70R14

+6.0% diameter, 0.0" width

185/80R14 is 25.65" tall vs 24.20". More than the 3% rule of thumb, so check carefully before switching.

24.2"14" rim5.1"7.3" wide
185/70R14 (solid) compared with 185/80R14 (dashed outline), drawn to scale

With 185/80R14 tires, when your speedometer says 60 mph you are really going

63.6 mph

185/80R14 is +1.46 inches (+6.0%) in overall diameter. That is more than the 3% most shops and makers recommend.

185/70R14185/80R14Difference%
Overall diameter24.20"25.65"+1.46"+6.0%
Section width7.28"7.28"0.00"0.0%
Sidewall height5.10"5.83"+0.73"+14.3%
Circumference76.02"80.59"+4.58"+6.0%
Revolutions per mile833.5786.2−47.3−5.7%

Speedometer difference

If your vehicle came with 185/70R14 and you fit 185/80R14, 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 mph68.9 mph+3.9 mph
70 mph74.2 mph+4.2 mph
75 mph79.5 mph+4.5 mph
80 mph84.8 mph+4.8 mph

Each size on its own

Questions

Which is bigger, 185/70R14 or 185/80R14?
185/80R14 is taller by 1.46 inches (25.65" vs 24.20"). 185/70R14 is the same width.
Can I replace 185/70R14 with 185/80R14?
It is not recommended without checking carefully. The diameter difference is +6.0%, 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 185/80R14 change my speedometer?
When your speedometer reads 60 mph with 185/80R14 fitted (calibrated for 185/70R14), your real speed is 63.6 mph. Your odometer will under-count miles by about 6.0%.
Will 185/80R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.73 inches of ground clearance at the axle.

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