295/40R20 vs 265/45R20

Q: Can I replace 295/40R20 with 265/45R20?

265/45R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +0.34%.

265/45R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +0.34%.

295/40R20 29.29" · 265/45R20 29.39" · drawn to scale

Side by side

	295/40R20	265/45R20	Difference
Overall diameter	29.29"	29.39"	+0.10" (+0.34%)
Section width	295 mm	265 mm	-30 mm
Sidewall	4.65"	4.69"	+0.05"
Rim	20"	20"	same
Circumference	92.0"	92.3"	+0.3"
Revs per mile	689	686	-2
Ride height	—	—	+0.05"
Speedometer reads 60 mph	60.0	60.2	+0.2 mph

Speedometer and odometer

With 265/45R20 on a car calibrated for 295/40R20, the speedometer reads 59.8 mph when you're really doing 60, and the odometer under-counts by 0.3%.

Speedo shows	Actual speed
30 mph	30.1 mph
45 mph	45.2 mph
60 mph	60.2 mph
70 mph	70.2 mph
80 mph	80.3 mph

Other sizes close to 295/40R20

Questions

Can I replace 295/40R20 with 265/45R20?

265/45R20 is a safe swap for 295/40R20 by the usual ±3% rule: the diameter differs by +0.34%.

What's the difference between 295/40R20 and 265/45R20?

265/45R20 is 0.10" taller and 30 mm narrower; the sidewall is +0.05". At an indicated 60 mph you'd actually be doing 60.2 mph.

Will 265/45R20 fit on 295/40R20 wheels?

Both use a 20" rim, so the wheel diameter matches; check the wheel's width range for a 265 mm tire and the fender clearance.