CarSpecsHQ

245/40R19 vs 275/40R19

275/40R19 is outside the ±3% rule as a replacement for 245/40R19: the diameter differs by +3.54%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
245/40R19 26.72" · 275/40R19 27.66" · drawn to scale

Side by side

245/40R19275/40R19Difference
Overall diameter26.72"27.66"+0.94" (+3.54%)
Section width245 mm275 mm+30 mm
Sidewall3.86"4.33"+0.47"
Rim19"19"same
Circumference83.9"86.9"+3.0"
Revs per mile755729-26
Ride height——+0.47"
Speedometer reads 60 mph60.062.1+2.1 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.1 mph

With 275/40R19 on a car calibrated for 245/40R19, the speedometer reads 58.0 mph when you're really doing 60, and the odometer under-counts by 3.5%.

Speedo showsActual speed
30 mph31.1 mph
45 mph46.6 mph
60 mph62.1 mph
70 mph72.5 mph
80 mph82.8 mph

Other sizes close to 245/40R19

Questions

Can I replace 245/40R19 with 275/40R19?

275/40R19 is outside the ±3% rule as a replacement for 245/40R19: the diameter differs by +3.54%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 245/40R19 and 275/40R19?

275/40R19 is 0.94" taller and 30 mm wider; the sidewall is +0.47". At an indicated 60 mph you'd actually be doing 62.1 mph.

Will 275/40R19 fit on 245/40R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 275 mm tire and the fender clearance.