CarSpecsHQ

275/60R20 vs 285/60R20

285/60R20 is a safe swap for 275/60R20 by the usual ±3% rule: the diameter differs by +1.43%.

20" rim
275/60R20 32.99" · 285/60R20 33.46" · drawn to scale

Side by side

275/60R20285/60R20Difference
Overall diameter32.99"33.46"+0.47" (+1.43%)
Section width275 mm285 mm+10 mm
Sidewall6.50"6.73"+0.24"
Rim20"20"same
Circumference103.6"105.1"+1.5"
Revs per mile611603-9
Ride height——+0.24"
Speedometer reads 60 mph60.060.9+0.9 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.9 mph

With 285/60R20 on a car calibrated for 275/60R20, the speedometer reads 59.2 mph when you're really doing 60, and the odometer under-counts by 1.4%.

Speedo showsActual speed
30 mph30.4 mph
45 mph45.6 mph
60 mph60.9 mph
70 mph71.0 mph
80 mph81.1 mph

Other sizes close to 275/60R20

Questions

Can I replace 275/60R20 with 285/60R20?

285/60R20 is a safe swap for 275/60R20 by the usual ±3% rule: the diameter differs by +1.43%.

What's the difference between 275/60R20 and 285/60R20?

285/60R20 is 0.47" taller and 10 mm wider; the sidewall is +0.24". At an indicated 60 mph you'd actually be doing 60.9 mph.

Will 285/60R20 fit on 275/60R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 285 mm tire and the fender clearance.