265/45R20
265/45R20 ships as an OEM size on the Porsche Macan, Tesla Model X. At 29.39″ diameter with a 4.69″ sidewall (45% of section width), this size turns 686 revolutions per mile.
About 265/45R20
Factory fitments for 265/45R20 include the Porsche Macan, Tesla Model X — meaning replacement tires in this size see steady demand and broad brand availability. At 29.39″ overall diameter, 265/45R20 turns 686 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 45% 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 255/45R20 drops diameter by 1.21%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 245/50R20 adds 0.87% 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 29.39″ stock diameter (about ±2% in percentage terms) will keep ABS, TPMS, and odometer readings inside the vehicle's designed tolerance.
Compare with another size
275/65R18 or "33" for inch aliases265/45R20
- Diameter
- 29.39″ / 746.5mm
- Section Width
- 10.43″
- Sidewall
- 4.69″ / 119.25mm
- Circumference
- 92.33″
- Revs/Mile
- 686
245/45R20
- Diameter
- 28.68″ / 728.5mm
- Section Width
- 9.65″
- Sidewall
- 4.34″ / 110.25mm
- Circumference
- 90.1″
- Revs/Mile
- 703
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.55 mph (94.23 km/h). Your speedometer reads 2.41% high versus actual speed.