CarSpecsHQ

225/45R19 vs 255/35R20

255/35R20 is a safe swap for 225/45R19 by the usual ±3% rule: the diameter differs by +0.20%.

19" → 20"
225/45R19 26.97" · 255/35R20 27.03" · drawn to scale

Side by side

225/45R19255/35R20Difference
Overall diameter26.97"27.03"+0.06" (+0.20%)
Section width225 mm255 mm+30 mm
Sidewall3.99"3.51"-0.47"
Rim19"20"+1"
Circumference84.7"84.9"+0.2"
Revs per mile748746-2
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 255/35R20 on a car calibrated for 225/45R19, the speedometer reads 59.9 mph when you're really doing 60, and the odometer under-counts by 0.2%.

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

Other sizes close to 225/45R19

Questions

Can I replace 225/45R19 with 255/35R20?

255/35R20 is a safe swap for 225/45R19 by the usual ±3% rule: the diameter differs by +0.20%.

What's the difference between 225/45R19 and 255/35R20?

255/35R20 is 0.06" taller and 30 mm wider; the sidewall is -0.47". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 255/35R20 fit on 225/45R19 wheels?

No — 225/45R19 needs a 19" wheel and 255/35R20 a 20" wheel. This is a plus/minus-size swap that changes wheels too.