275/50R20
275/50R20 ships as an OEM size on the BMW X7, Mercedes-Benz GLE. At 30.83″ diameter with a 5.41″ sidewall (50% of section width), this size turns 654 revolutions per mile.
About 275/50R20
Factory fitments for 275/50R20 include the BMW X7, Mercedes-Benz GLE — meaning replacement tires in this size see steady demand and broad brand availability. At 30.83″ overall diameter, 275/50R20 turns 654 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 50% aspect ratio gives it a moderate sidewall suited to sporty street driving and responsive turn-in. 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 265/50R20 drops diameter by 1.28%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 255/55R20 adds 0.70% 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 30.83″ 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 aliases275/50R20
- Diameter
- 30.83″ / 783mm
- Section Width
- 10.83″
- Sidewall
- 5.41″ / 137.5mm
- Circumference
- 96.85″
- Revs/Mile
- 654
255/50R20
- Diameter
- 30.04″ / 763mm
- Section Width
- 10.04″
- Sidewall
- 5.02″ / 127.5mm
- Circumference
- 94.37″
- Revs/Mile
- 671
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.47 mph (94.09 km/h). Your speedometer reads 2.55% high versus actual speed.