265/70R17 vs 235/85R16

Q: Can I replace 265/70R17 with 235/85R16?

235/85R16 is a safe swap for 265/70R17 by the usual ±3% rule: the diameter differs by +0.39%.

235/85R16 is a safe swap for 265/70R17 by the usual ±3% rule: the diameter differs by +0.39%.

265/70R17 31.61" · 235/85R16 31.73" · drawn to scale

Side by side

	265/70R17	235/85R16	Difference
Overall diameter	31.61"	31.73"	+0.12" (+0.39%)
Section width	265 mm	235 mm	-30 mm
Sidewall	7.30"	7.86"	+0.56"
Rim	17"	16"	-1"
Circumference	99.3"	99.7"	+0.4"
Revs per mile	638	636	-2
Ride height	—	—	+0.06"
Speedometer reads 60 mph	60.0	60.2	+0.2 mph

Speedometer and odometer

With 235/85R16 on a car calibrated for 265/70R17, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.4%.

Speedo shows	Actual speed
30 mph	30.1 mph
45 mph	45.2 mph
60 mph	60.2 mph
70 mph	70.3 mph
80 mph	80.3 mph

Other sizes close to 265/70R17

Questions

Can I replace 265/70R17 with 235/85R16?

235/85R16 is a safe swap for 265/70R17 by the usual ±3% rule: the diameter differs by +0.39%.

What's the difference between 265/70R17 and 235/85R16?

235/85R16 is 0.12" taller and 30 mm narrower; the sidewall is +0.56". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 235/85R16 fit on 265/70R17 wheels?

No — 265/70R17 needs a 17" wheel and 235/85R16 a 16" wheel. This is a plus/minus-size swap that changes wheels too.