CarSpecsHQ

205/45R17 vs 235/45R17

235/45R17 is outside the ±3% rule as a replacement for 205/45R17: the diameter differs by +4.38%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

17" rim
205/45R17 24.26" · 235/45R17 25.33" · drawn to scale

Side by side

205/45R17235/45R17Difference
Overall diameter24.26"25.33"+1.06" (+4.38%)
Section width205 mm235 mm+30 mm
Sidewall3.63"4.16"+0.53"
Rim17"17"same
Circumference76.2"79.6"+3.3"
Revs per mile831796-35
Ride height——+0.53"
Speedometer reads 60 mph60.062.6+2.6 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.6 mph

With 235/45R17 on a car calibrated for 205/45R17, the speedometer reads 57.5 mph when you're really doing 60, and the odometer under-counts by 4.4%.

Speedo showsActual speed
30 mph31.3 mph
45 mph47.0 mph
60 mph62.6 mph
70 mph73.1 mph
80 mph83.5 mph

Other sizes close to 205/45R17

Questions

Can I replace 205/45R17 with 235/45R17?

235/45R17 is outside the ±3% rule as a replacement for 205/45R17: the diameter differs by +4.38%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 205/45R17 and 235/45R17?

235/45R17 is 1.06" taller and 30 mm wider; the sidewall is +0.53". At an indicated 60 mph you'd actually be doing 62.6 mph.

Will 235/45R17 fit on 205/45R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.