CarSpecsHQ

345/30R19 vs 295/40R19

295/40R19 is outside the ±3% rule as a replacement for 345/30R19: the diameter differs by +4.21%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

19" rim
345/30R19 27.15" · 295/40R19 28.29" · drawn to scale

Side by side

345/30R19295/40R19Difference
Overall diameter27.15"28.29"+1.14" (+4.21%)
Section width345 mm295 mm-50 mm
Sidewall4.07"4.65"+0.57"
Rim19"19"same
Circumference85.3"88.9"+3.6"
Revs per mile743713-30
Ride height——+0.57"
Speedometer reads 60 mph60.062.5+2.5 mph

Speedometer and odometer

020406080100120 reads 60 · actual 62.5 mph

With 295/40R19 on a car calibrated for 345/30R19, the speedometer reads 57.6 mph when you're really doing 60, and the odometer under-counts by 4.2%.

Speedo showsActual speed
30 mph31.3 mph
45 mph46.9 mph
60 mph62.5 mph
70 mph72.9 mph
80 mph83.4 mph

Other sizes close to 345/30R19

Questions

Can I replace 345/30R19 with 295/40R19?

295/40R19 is outside the ±3% rule as a replacement for 345/30R19: the diameter differs by +4.21%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 345/30R19 and 295/40R19?

295/40R19 is 1.14" taller and 50 mm narrower; the sidewall is +0.57". At an indicated 60 mph you'd actually be doing 62.5 mph.

Will 295/40R19 fit on 345/30R19 wheels?

Both use a 19" rim, so the wheel diameter matches; check the wheel's width range for a 295 mm tire and the fender clearance.