Tire Size Box

205/70R16 vs 205/80R16

205/80R16 compared with 205/70R16

+5.9% diameter, 0.0" width

205/80R16 is 28.91" tall vs 27.30". More than the 3% rule of thumb, so check carefully before switching.

27.3"16" rim5.6"8.1" wide
205/70R16 (solid) compared with 205/80R16 (dashed outline), drawn to scale

With 205/80R16 tires, when your speedometer says 60 mph you are really going

63.5 mph

205/80R16 is +1.61 inches (+5.9%) in overall diameter. That is more than the 3% most shops and makers recommend.

205/70R16205/80R16Difference%
Overall diameter27.30"28.91"+1.61"+5.9%
Section width8.07"8.07"0.00"0.0%
Sidewall height5.65"6.46"+0.81"+14.3%
Circumference85.76"90.83"+5.07"+5.9%
Revolutions per mile738.8697.5−41.2−5.6%

Speedometer difference

If your vehicle came with 205/70R16 and you fit 205/80R16, 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 mph63.5 mph+3.5 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, 205/70R16 or 205/80R16?
205/80R16 is taller by 1.61 inches (28.91" vs 27.30"). 205/70R16 is the same width.
Can I replace 205/70R16 with 205/80R16?
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 205/80R16 change my speedometer?
When your speedometer reads 60 mph with 205/80R16 fitted (calibrated for 205/70R16), your real speed is 63.5 mph. Your odometer will under-count miles by about 5.9%.
Will 205/80R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.81 inches of ground clearance at the axle.

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