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275/40R20

275/40R20 ships as an OEM size on the Dodge Challenger, Dodge Charger. At 28.66″ diameter with a 4.33″ sidewall (40% of section width), this size turns 704 revolutions per mile.

Overall diameter
28.66″
728 mm
Section width
10.83″
275 mm
Sidewall
4.33″
110 mm
Circumference
90.04″
Revs / mile
704
Rim
20″

About 275/40R20

Factory fitments for 275/40R20 include the Dodge Challenger, Dodge Charger — meaning replacement tires in this size see steady demand and broad brand availability. At 28.66″ overall diameter, 275/40R20 turns 704 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 40% aspect ratio gives it a low-profile sidewall that delivers sharp steering response but transmits road imperfections. The 20″ rim pairing is typical for luxury SUV and performance-oriented platforms, so compatible wheels are easy to source new or used. Going one step shorter to 265/40R20 drops diameter by 1.10%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 285/40R20 adds 1.10% diameter — also inside the safe window, with marginally taller ride height. If you are shopping for a direct replacement, any tire within roughly ±0.7″ of the 28.66″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.

Compare with another size

Type to search · try 275/65R18 or "33" for inch aliases
Common upsizes from 275/40R20:
Don't know your stock size? Load it by vehicle:

275/40R20

Diameter
28.66″ / 728mm
Section Width
10.83
Sidewall
4.33″ / 110mm
Circumference
90.04
Revs/Mile
704
See tires in 275/40R20

255/40R20

Diameter
28.03″ / 712mm
Section Width
10.04
Sidewall
4.02″ / 102mm
Circumference
88.06
Revs/Mile
719
See tires in 255/40R20
275/40R20 · 28.66255/40R20 · 28.03

Speedometer & Diameter Impact

Diameter Change
-2.20%
Sidewall Change
-0.31″
Revs/Mile Δ
15
mph

At an indicated 60 mph, your actual speed is 58.68 mph (94.44 km/h). Your speedometer reads 2.20% high versus actual speed.

Vehicles that fit 275/40R20

Similar sizes on the same rim

Speedometer impact if you upsize from 275/40R20