CarSpecsHQ

235/55R17 vs 205/70R16

205/70R16 is a safe swap for 235/55R17 by the usual ±3% rule: the diameter differs by +0.45%.

17" → 16"
235/55R17 27.18" · 205/70R16 27.30" · drawn to scale

Side by side

235/55R17205/70R16Difference
Overall diameter27.18"27.30"+0.12" (+0.45%)
Section width235 mm205 mm-30 mm
Sidewall5.09"5.65"+0.56"
Rim17"16"-1"
Circumference85.4"85.8"+0.4"
Revs per mile742739-3
Ride height——+0.06"
Speedometer reads 60 mph60.060.3+0.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.3 mph

With 205/70R16 on a car calibrated for 235/55R17, the speedometer reads 59.7 mph when you're really doing 60, and the odometer under-counts by 0.4%.

Speedo showsActual speed
30 mph30.1 mph
45 mph45.2 mph
60 mph60.3 mph
70 mph70.3 mph
80 mph80.4 mph

Other sizes close to 235/55R17

Questions

Can I replace 235/55R17 with 205/70R16?

205/70R16 is a safe swap for 235/55R17 by the usual ±3% rule: the diameter differs by +0.45%.

What's the difference between 235/55R17 and 205/70R16?

205/70R16 is 0.12" taller and 30 mm narrower; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 60.3 mph.

Will 205/70R16 fit on 235/55R17 wheels?

No — 235/55R17 needs a 17" wheel and 205/70R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.