CarSpecsHQ

225/35R20 vs 235/40R19

235/40R19 is a safe swap for 225/35R20 by the usual ±3% rule: the diameter differs by +0.77%.

20" → 19"
225/35R20 26.20" · 235/40R19 26.40" · drawn to scale

Side by side

225/35R20235/40R19Difference
Overall diameter26.20"26.40"+0.20" (+0.77%)
Section width225 mm235 mm+10 mm
Sidewall3.10"3.70"+0.60"
Rim20"19"-1"
Circumference82.3"82.9"+0.6"
Revs per mile770764-6
Ride height——+0.10"
Speedometer reads 60 mph60.060.5+0.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.5 mph

With 235/40R19 on a car calibrated for 225/35R20, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.

Speedo showsActual speed
30 mph30.2 mph
45 mph45.3 mph
60 mph60.5 mph
70 mph70.5 mph
80 mph80.6 mph

Other sizes close to 225/35R20

Questions

Can I replace 225/35R20 with 235/40R19?

235/40R19 is a safe swap for 225/35R20 by the usual ±3% rule: the diameter differs by +0.77%.

What's the difference between 225/35R20 and 235/40R19?

235/40R19 is 0.20" taller and 10 mm wider; the sidewall is +0.60". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 235/40R19 fit on 225/35R20 wheels?

No — 225/35R20 needs a 20" wheel and 235/40R19 a 19" wheel. This is a plus/minus-size swap that changes wheels too.