Skip to content
GizmoDriver

205/60R17 vs 275/40R18 tire size

275/40R18 vs 205/60R17, diameter

Same diameter

Speedometer
60.1 mph
At a true 60 mph
Diameter
26.66 in
Was 26.69 in
Revs per mile
756
Was 756
3% guideline
Within

Car built for 205/60R17, now on 275/40R18.

205/60R17 and 275/40R18

205/60R17 vs 275/40R18 tire size
Measure205/60R17275/40R18Difference
Width, mm205275+70
Sidewall, % of width6040-20
Rim, in1718+1
Section height, in4.844.33-0.51
Diameter, in26.6926.66-0.02 (-0.1%)
Circumference, in83.883.8-0.1
Revs per mile756756+1 (+0.1%)

Fitting 275/40R18 instead of 205/60R17

Within the usual 3% diameter guideline.

  • Needs 18 in wheels.
  • 70 mm wider. Check rubbing at full lock.
  • Shorter sidewall: 0.5 in less.

Cars with 275/40R18

What this cannot tell you

Diameter within 3% is a common shop guideline, not a maker spec.

Load index, offset and clearance are not in this data.

How values are checked