Tire Size Box

245/80R14 vs 245/85R14

245/85R14 compared with 245/80R14

+3.3% diameter, 0.0" width

245/85R14 is 30.40" tall vs 29.43". More than the 3% rule of thumb, so check carefully before switching.

29.4"14" rim7.7"9.6" wide
245/80R14 (solid) compared with 245/85R14 (dashed outline), drawn to scale

With 245/85R14 tires, when your speedometer says 60 mph you are really going

62.0 mph

245/85R14 is +0.96 inches (+3.3%) in overall diameter. That is more than the 3% most shops and makers recommend.

245/80R14245/85R14Difference%
Overall diameter29.43"30.40"+0.96"+3.3%
Section width9.65"9.65"0.00"0.0%
Sidewall height7.72"8.20"+0.48"+6.3%
Circumference92.47"95.50"+3.03"+3.3%
Revolutions per mile685.2663.5−21.7−3.2%

Speedometer difference

If your vehicle came with 245/80R14 and you fit 245/85R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.7 mph+0.7 mph
30 mph31.0 mph+1.0 mph
40 mph41.3 mph+1.3 mph
50 mph51.6 mph+1.6 mph
60 mph62.0 mph+2.0 mph
65 mph67.1 mph+2.1 mph
70 mph72.3 mph+2.3 mph
75 mph77.5 mph+2.5 mph
80 mph82.6 mph+2.6 mph

Each size on its own

Questions

Which is bigger, 245/80R14 or 245/85R14?
245/85R14 is taller by 0.96 inches (30.40" vs 29.43"). 245/80R14 is the same width.
Can I replace 245/80R14 with 245/85R14?
It is not recommended without checking carefully. The diameter difference is +3.3%, 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 245/85R14 change my speedometer?
When your speedometer reads 60 mph with 245/85R14 fitted (calibrated for 245/80R14), your real speed is 62.0 mph. Your odometer will under-count miles by about 3.3%.
Will 245/85R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.48 inches of ground clearance at the axle.

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