CarSpecsHQ

255/30R22 vs 315/30R22

315/30R22 is outside the ±3% rule as a replacement for 255/30R22: the diameter differs by +5.06%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

22" rim
255/30R22 28.02" · 315/30R22 29.44" · drawn to scale

Side by side

255/30R22315/30R22Difference
Overall diameter28.02"29.44"+1.42" (+5.06%)
Section width255 mm315 mm+60 mm
Sidewall3.01"3.72"+0.71"
Rim22"22"same
Circumference88.0"92.5"+4.5"
Revs per mile720685-35
Ride height——+0.71"
Speedometer reads 60 mph60.063.0+3.0 mph

Speedometer and odometer

020406080100120 reads 60 · actual 63.0 mph

With 315/30R22 on a car calibrated for 255/30R22, the speedometer reads 57.1 mph when you're really doing 60, and the odometer under-counts by 5.1%.

Speedo showsActual speed
30 mph31.5 mph
45 mph47.3 mph
60 mph63.0 mph
70 mph73.5 mph
80 mph84.0 mph

Other sizes close to 255/30R22

Questions

Can I replace 255/30R22 with 315/30R22?

315/30R22 is outside the ±3% rule as a replacement for 255/30R22: the diameter differs by +5.06%, so the speedometer, odometer and ABS calibration will be off and clearance needs checking.

What's the difference between 255/30R22 and 315/30R22?

315/30R22 is 1.42" taller and 60 mm wider; the sidewall is +0.71". At an indicated 60 mph you'd actually be doing 63.0 mph.

Will 315/30R22 fit on 255/30R22 wheels?

Both use a 22" rim, so the wheel diameter matches; check the wheel's width range for a 315 mm tire and the fender clearance.