295/25R22 vs 255/35R21

Q: Can I replace 295/25R22 with 255/35R21?

255/35R21 is a safe swap for 295/25R22 by the usual ±3% rule: the diameter differs by +0.79%.

255/35R21 is a safe swap for 295/25R22 by the usual ±3% rule: the diameter differs by +0.79%.

295/25R22 27.81" · 255/35R21 28.03" · drawn to scale

Side by side

	295/25R22	255/35R21	Difference
Overall diameter	27.81"	28.03"	+0.22" (+0.79%)
Section width	295 mm	255 mm	-40 mm
Sidewall	2.90"	3.51"	+0.61"
Rim	22"	21"	-1"
Circumference	87.4"	88.1"	+0.7"
Revs per mile	725	720	-6
Ride height	—	—	+0.11"
Speedometer reads 60 mph	60.0	60.5	+0.5 mph

Speedometer and odometer

With 255/35R21 on a car calibrated for 295/25R22, the speedometer reads 59.5 mph when you're really doing 60, and the odometer under-counts by 0.8%.

Speedo shows	Actual speed
30 mph	30.2 mph
45 mph	45.4 mph
60 mph	60.5 mph
70 mph	70.6 mph
80 mph	80.6 mph

Other sizes close to 295/25R22

Questions

Can I replace 295/25R22 with 255/35R21?

255/35R21 is a safe swap for 295/25R22 by the usual ±3% rule: the diameter differs by +0.79%.

What's the difference between 295/25R22 and 255/35R21?

255/35R21 is 0.22" taller and 40 mm narrower; the sidewall is +0.61". At an indicated 60 mph you'd actually be doing 60.5 mph.

Will 255/35R21 fit on 295/25R22 wheels?

No — 295/25R22 needs a 22" wheel and 255/35R21 a 21" wheel. This is a plus/minus-size swap that changes wheels too.