255/70R15 vs 275/60R15

255/70R15 is 1.1" taller than 275/60R15 (3.7%)

Diameter difference−3.66%diameter 29.06" → 27.99"
255/70R15275/60R15
255/70R15275/60R15Difference
Overall diameter29.06"27.99"−1.06"
Section width10.04"10.83"+0.79"
Sidewall height7.03"6.50"−0.53"
Circumference91.3"87.9"−3.3"
Revolutions per mile694720+26
Wheel diameter15"15"±0"

Speedometer

ShowsActualDiff
30 mph28.9 mph−1.1
45 mph43.4 mph−1.6
60 mph57.8 mph−2.2
70 mph67.4 mph−2.6
80 mph77.1 mph−2.9

Gear ratio to match

CurrentEquivalent
3.423.29
3.553.42
3.733.59
4.103.95

275/60R15 is 1.06" shorter than 255/70R15, a −3.66% change in diameter. That is more than the 3% many tire shops use as a limit, so plan on recalibrating the speedometer and checking ABS and stability control.

Ground clearance changes by 0.53" (half the diameter change), and the tire needs 0.53" less room above it.

275/60R15 is 0.79" wider. On the same wheel offset about half of that, 0.39", moves toward the suspension and half toward the fender.

Both fit a 15" wheel; the sidewall is 0.53" shorter on 275/60R15.

Details: 255/70R15 in inches · 275/60R15 in inches · change sizes in the calculator

FAQ

What is the difference between 255/70R15 and 275/60R15?

275/60R15 is 1.06" shorter (−3.66%) and 0.79" wider than 255/70R15.

Will 275/60R15 change my speedometer?

Yes, by −3.66%. When the speedometer shows 60 mph you would be going 57.8 mph.

Can I replace 255/70R15 with 275/60R15?

It is a −3.7% diameter change, larger than the common 3% guideline, so check clearance and plan to recalibrate.