215/75R15 vs 235/70R15

Q: Can I replace 215/75R15 with 235/70R15?

235/70R15 is a safe swap for 215/75R15 by the usual ±3% rule: the diameter differs by +0.92%.

235/70R15 is a safe swap for 215/75R15 by the usual ±3% rule: the diameter differs by +0.92%.

215/75R15 27.70" · 235/70R15 27.95" · drawn to scale

Side by side

	215/75R15	235/70R15	Difference
Overall diameter	27.70"	27.95"	+0.26" (+0.92%)
Section width	215 mm	235 mm	+20 mm
Sidewall	6.35"	6.48"	+0.13"
Rim	15"	15"	same
Circumference	87.0"	87.8"	+0.8"
Revs per mile	728	722	-7
Ride height	—	—	+0.13"
Speedometer reads 60 mph	60.0	60.6	+0.6 mph

Speedometer and odometer

With 235/70R15 on a car calibrated for 215/75R15, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.9%.

Speedo shows	Actual speed
30 mph	30.3 mph
45 mph	45.4 mph
60 mph	60.6 mph
70 mph	70.6 mph
80 mph	80.7 mph

Other sizes close to 215/75R15

Questions

Can I replace 215/75R15 with 235/70R15?

235/70R15 is a safe swap for 215/75R15 by the usual ±3% rule: the diameter differs by +0.92%.

What's the difference between 215/75R15 and 235/70R15?

235/70R15 is 0.26" taller and 20 mm wider; the sidewall is +0.13". At an indicated 60 mph you'd actually be doing 60.6 mph.

Will 235/70R15 fit on 215/75R15 wheels?

Both use a 15" rim, so the wheel diameter matches; check the wheel's width range for a 235 mm tire and the fender clearance.