CarSpecsHQ

275/45R19 vs 245/55R19

245/55R19 is outside the ±3% rule as a replacement for 275/45R19: the diameter differs by +3.01%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
275/45R19 28.74" · 245/55R19 29.61" · drawn to scale

Side by side

275/45R19245/55R19Difference
Overall diameter28.74"29.61"+0.87" (+3.01%)
Section width275 mm245 mm-30 mm
Sidewall4.87"5.31"+0.43"
Rim19"19"same
Circumference90.3"93.0"+2.7"
Revs per mile702681-21
Ride height——+0.43"
Speedometer reads 60 mph60.061.8+1.8 mph

Speedometer and odometer

020406080100120 reads 60 · actual 61.8 mph

With 245/55R19 on a car calibrated for 275/45R19, the speedometer reads 58.2 mph when you're really doing 60, and the odometer under-counts by 3.0%.

Speedo showsActual speed
30 mph30.9 mph
45 mph46.4 mph
60 mph61.8 mph
70 mph72.1 mph
80 mph82.4 mph

Other sizes close to 275/45R19

Questions

Can I replace 275/45R19 with 245/55R19?

245/55R19 is outside the ±3% rule as a replacement for 275/45R19: the diameter differs by +3.01%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 275/45R19 and 245/55R19?

245/55R19 is 0.87" taller and 30 mm narrower; the sidewall is +0.43". At an indicated 60 mph you'd actually be doing 61.8 mph.

Will 245/55R19 fit on 275/45R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 245 mm tire and the fender clearance.