Tire Size Box

245/65R14 vs 235/70R14

235/70R14 compared with 245/65R14

+1.6% diameter, −0.4" width

235/70R14 is 26.95" tall vs 26.54". Within the 3% rule, so usually interchangeable.

26.5"14" rim6.3"9.6" wide
245/65R14 (solid) compared with 235/70R14 (dashed outline), drawn to scale

With 235/70R14 tires, when your speedometer says 60 mph you are really going

60.9 mph

235/70R14 is +0.41 inches (+1.6%) in overall diameter. That is within the 3% most shops and makers allow.

245/65R14235/70R14Difference%
Overall diameter26.54"26.95"+0.41"+1.6%
Section width9.65"9.25"−0.39"−4.1%
Sidewall height6.27"6.48"+0.21"+3.3%
Circumference83.38"84.67"+1.30"+1.6%
Revolutions per mile759.9748.3−11.7−1.5%

Speedometer difference

If your vehicle came with 245/65R14 and you fit 235/70R14, here is your real speed for each speedometer reading:

Speedometer showsActual speedDifference
20 mph20.3 mph+0.3 mph
30 mph30.5 mph+0.5 mph
40 mph40.6 mph+0.6 mph
50 mph50.8 mph+0.8 mph
60 mph60.9 mph+0.9 mph
65 mph66.0 mph+1.0 mph
70 mph71.1 mph+1.1 mph
75 mph76.2 mph+1.2 mph
80 mph81.2 mph+1.2 mph

Each size on its own

Questions

Which is bigger, 245/65R14 or 235/70R14?
235/70R14 is taller by 0.41 inches (26.95" vs 26.54"). 245/65R14 is wider by 0.39 inches.
Can I replace 245/65R14 with 235/70R14?
Usually, yes. The diameter difference is +1.6%, inside the 3% rule of thumb most tire shops use. Check that the wider or taller tire clears your suspension and fenders, and that its load index meets your placard.
How much will 235/70R14 change my speedometer?
When your speedometer reads 60 mph with 235/70R14 fitted (calibrated for 245/65R14), your real speed is 60.9 mph. Your odometer will under-count miles by about 1.6%.
Will 235/70R14 lift my vehicle?
Ride height changes by half the diameter difference: +0.21 inches of ground clearance at the axle.

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