CarSpecsHQ

335/30R18 vs 225/45R18

225/45R18 is a safe swap for 335/30R18 by the usual ±3% rule: the diameter differs by +0.23%.

18" rim
335/30R18 25.91" · 225/45R18 25.97" · drawn to scale

Side by side

335/30R18225/45R18Difference
Overall diameter25.91"25.97"+0.06" (+0.23%)
Section width335 mm225 mm-110 mm
Sidewall3.96"3.99"+0.03"
Rim18"18"same
Circumference81.4"81.6"+0.2"
Revs per mile778777-2
Ride height——+0.03"
Speedometer reads 60 mph60.060.1+0.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 60.1 mph

With 225/45R18 on a car calibrated for 335/30R18, 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 mph70.2 mph
80 mph80.2 mph

Other sizes close to 335/30R18

Questions

Can I replace 335/30R18 with 225/45R18?

225/45R18 is a safe swap for 335/30R18 by the usual ±3% rule: the diameter differs by +0.23%.

What's the difference between 335/30R18 and 225/45R18?

225/45R18 is 0.06" taller and 110 mm narrower; the sidewall is +0.03". At an indicated 60 mph you'd actually be doing 60.1 mph.

Will 225/45R18 fit on 335/30R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 225 mm tire and the fender clearance.