CarSpecsHQ

255/80R17 vs 255/85R16

255/85R16 is a safe swap for 255/80R17 by the usual ±3% rule: the diameter differs by +0.01%.

17" → 16"
255/80R17 33.06" · 255/85R16 33.07" · drawn to scale

Side by side

255/80R17255/85R16Difference
Overall diameter33.06"33.07"+0.00" (+0.01%)
Section width255 mm255 mm0 mm
Sidewall8.03"8.53"+0.50"
Rim17"16"-1"
Circumference103.9"103.9"+0.0"
Revs per mile610610-0
Ride height——+0.00"
Speedometer reads 60 mph60.060.0+0.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.0 mph

With 255/85R16 on a car calibrated for 255/80R17, the speedometer reads 60.0 mph when you're really doing 60, and the odometer under-counts by 0.0%.

Speedo showsActual speed
30 mph30.0 mph
45 mph45.0 mph
60 mph60.0 mph
70 mph70.0 mph
80 mph80.0 mph

Other sizes close to 255/80R17

Questions

Can I replace 255/80R17 with 255/85R16?

255/85R16 is a safe swap for 255/80R17 by the usual ±3% rule: the diameter differs by +0.01%.

What's the difference between 255/80R17 and 255/85R16?

255/85R16 is 0.00" taller and 0 mm wider; the sidewall is +0.50". At an indicated 60 mph you'd actually be doing 60.0 mph.

Will 255/85R16 fit on 255/80R17 wheels?

No — 255/80R17 needs a 17" wheel and 255/85R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.