CarSpecsHQ

295/35R18 vs 245/45R18

245/45R18 is a safe swap for 295/35R18 by the usual ±3% rule: the diameter differs by +2.11%.

18" rim
295/35R18 26.13" · 245/45R18 26.68" · drawn to scale

Side by side

295/35R18245/45R18Difference
Overall diameter26.13"26.68"+0.55" (+2.11%)
Section width295 mm245 mm-50 mm
Sidewall4.06"4.34"+0.28"
Rim18"18"same
Circumference82.1"83.8"+1.7"
Revs per mile772756-16
Ride height——+0.28"
Speedometer reads 60 mph60.061.3+1.3 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.3 mph

With 245/45R18 on a car calibrated for 295/35R18, the speedometer reads 58.8 mph when you're really doing 60, and the odometer under-counts by 2.1%.

Speedo showsActual speed
30 mph30.6 mph
45 mph45.9 mph
60 mph61.3 mph
70 mph71.5 mph
80 mph81.7 mph

Other sizes close to 295/35R18

Questions

Can I replace 295/35R18 with 245/45R18?

245/45R18 is a safe swap for 295/35R18 by the usual ±3% rule: the diameter differs by +2.11%.

What's the difference between 295/35R18 and 245/45R18?

245/45R18 is 0.55" taller and 50 mm narrower; the sidewall is +0.28". At an indicated 60 mph you'd actually be doing 61.3 mph.

Will 245/45R18 fit on 295/35R18 wheels?

Both use a 18" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.