CarSpecsHQ

265/40R20 vs 275/40R20

275/40R20 is a safe swap for 265/40R20 by the usual ±3% rule: the diameter differs by +1.11%.

20" rim
265/40R20 28.35" · 275/40R20 28.66" · drawn to scale

Side by side

265/40R20275/40R20Difference
Overall diameter28.35"28.66"+0.31" (+1.11%)
Section width265 mm275 mm+10 mm
Sidewall4.17"4.33"+0.16"
Rim20"20"same
Circumference89.1"90.0"+1.0"
Revs per mile711704-8
Ride height——+0.16"
Speedometer reads 60 mph60.060.7+0.7 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.7 mph

With 275/40R20 on a car calibrated for 265/40R20, the speedometer reads 59.3 mph when you're really doing 60, and the odometer under-counts by 1.1%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.5 mph
60 mph60.7 mph
70 mph70.8 mph
80 mph80.9 mph

Other sizes close to 265/40R20

Questions

Can I replace 265/40R20 with 275/40R20?

275/40R20 is a safe swap for 265/40R20 by the usual ±3% rule: the diameter differs by +1.11%.

What's the difference between 265/40R20 and 275/40R20?

275/40R20 is 0.31" taller and 10 mm wider; the sidewall is +0.16". At an indicated 60 mph you'd actually be doing 60.7 mph.

Will 275/40R20 fit on 265/40R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.