Tire Size Box

245/70R16 vs 245/80R16

245/80R16 compared with 245/70R16

+6.5% diameter, 0.0" width

245/80R16 is 31.43" tall vs 29.50". More than the 3% rule of thumb, so check carefully before switching.

29.5"16" rim6.8"9.6" wide
245/70R16 (solid) compared with 245/80R16 (dashed outline), drawn to scale

With 245/80R16 tires, when your speedometer says 60 mph you are really going

63.9 mph

245/80R16 is +1.93 inches (+6.5%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/70R16245/80R16Difference%
Overall diameter29.50"31.43"+1.93"+6.5%
Section width9.65"9.65"0.00"0.0%
Sidewall height6.75"7.72"+0.96"+14.3%
Circumference92.69"98.75"+6.06"+6.5%
Revolutions per mile683.6641.6−42.0−6.1%

Speedometer difference

If your vehicle came with 245/70R16 and you fit 245/80R16, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph21.3 mph+1.3 mph
30 mph32.0 mph+2.0 mph
40 mph42.6 mph+2.6 mph
50 mph53.3 mph+3.3 mph
60 mph63.9 mph+3.9 mph
65 mph69.3 mph+4.3 mph
70 mph74.6 mph+4.6 mph
75 mph79.9 mph+4.9 mph
80 mph85.2 mph+5.2 mph

Each size on its own

Questions

Which is bigger, 245/70R16 or 245/80R16?
245/80R16 is taller by 1.93 inches (31.43" vs 29.50"). 245/70R16 is the same width.
Can I replace 245/70R16 with 245/80R16?
It is not recommended without checking carefully. The diameter difference is +6.5%, 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 245/80R16 change my speedometer?
When your speedometer reads 60 mph with 245/80R16 fitted (calibrated for 245/70R16), your real speed is 63.9 mph. Your odometer will under-count miles by about 6.5%.
Will 245/80R16 lift my vehicle?
Ride height changes by half the diameter difference: +0.96 inches of ground clearance at the axle.

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