315/35R17 vs 215/55R17

Q: Can I replace 315/35R17 with 215/55R17?

215/55R17 is a safe swap for 315/35R17 by the usual ±3% rule: the diameter differs by +2.45%.

215/55R17 is a safe swap for 315/35R17 by the usual ±3% rule: the diameter differs by +2.45%.

315/35R17 25.68" · 215/55R17 26.31" · drawn to scale

Side by side

	315/35R17	215/55R17	Difference
Overall diameter	25.68"	26.31"	+0.63" (+2.45%)
Section width	315 mm	215 mm	-100 mm
Sidewall	4.34"	4.66"	+0.31"
Rim	17"	17"	same
Circumference	80.7"	82.7"	+2.0"
Revs per mile	785	767	-19
Ride height	—	—	+0.31"
Speedometer reads 60 mph	60.0	61.5	+1.5 mph

Speedometer and odometer

With 215/55R17 on a car calibrated for 315/35R17, the speedometer reads 58.6 mph when you're really doing 60, and the odometer under-counts by 2.5%.

Speedo shows	Actual speed
30 mph	30.7 mph
45 mph	46.1 mph
60 mph	61.5 mph
70 mph	71.7 mph
80 mph	82.0 mph

Other sizes close to 315/35R17

Questions

Can I replace 315/35R17 with 215/55R17?

215/55R17 is a safe swap for 315/35R17 by the usual ±3% rule: the diameter differs by +2.45%.

What's the difference between 315/35R17 and 215/55R17?

215/55R17 is 0.63" taller and 100 mm narrower; the sidewall is +0.31". At an indicated 60 mph you'd actually be doing 61.5 mph.

Will 215/55R17 fit on 315/35R17 wheels?

Both use a 17" rim, so the wheel diameter matches; check the wheel's width range for a 215 mm tire and the fender clearance.