CarSpecsHQ

275/40R17 vs 205/55R17

205/55R17 is a safe swap for 275/40R17 by the usual ±3% rule: the diameter differs by +0.84%.

17" rim
275/40R17 25.66" · 205/55R17 25.88" · drawn to scale

Side by side

275/40R17205/55R17Difference
Overall diameter25.66"25.88"+0.22" (+0.84%)
Section width275 mm205 mm-70 mm
Sidewall4.33"4.44"+0.11"
Rim17"17"same
Circumference80.6"81.3"+0.7"
Revs per mile786779-7
Ride height——+0.11"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 205/55R17 on a car calibrated for 275/40R17, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.

Speedo showsActual speed
30 mph30.3 mph
45 mph45.4 mph
60 mph60.5 mph
70 mph70.6 mph
80 mph80.7 mph

Other sizes close to 275/40R17

Questions

Can I replace 275/40R17 with 205/55R17?

205/55R17 is a safe swap for 275/40R17 by the usual ±3% rule: the diameter differs by +0.84%.

What's the difference between 275/40R17 and 205/55R17?

205/55R17 is 0.22" taller and 70 mm narrower; the sidewall is +0.11". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 205/55R17 fit on 275/40R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 205 mm tire and the fender clearance.