235/55R17
235/55R17 ships as an OEM size on the Ford Mustang. At 27.18″ diameter with a 5.09″ sidewall (55% of section width), this size turns 742 revolutions per mile.
About 235/55R17
Factory fitments for 235/55R17 include the Ford Mustang — meaning replacement tires in this size see steady demand and broad brand availability. At 27.18″ overall diameter, 235/55R17 turns 742 revolutions per mile, which is the reference point the factory speedometer and odometer were calibrated against. The 55% aspect ratio gives it a moderate sidewall suited to sporty street driving and responsive turn-in. The 17″ rim pairing is typical for light-truck, crossover, and mid-size SUV applications, so compatible wheels are easy to source new or used. Going one step shorter to 215/60R17 drops diameter by 0.07%, which stays within the ±3% fitment safe zone for most vehicles. Stepping up to 225/60R17 adds 1.67% 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 27.18″ 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 aliases235/55R17
- Diameter
- 27.18″ / 690.3mm
- Section Width
- 9.25″
- Sidewall
- 5.09″ / 129.25mm
- Circumference
- 85.38″
- Revs/Mile
- 742
215/55R17
- Diameter
- 26.31″ / 668.3mm
- Section Width
- 8.46″
- Sidewall
- 4.66″ / 118.25mm
- Circumference
- 82.66″
- Revs/Mile
- 767
Speedometer & Diameter Impact
At an indicated 60 mph, your actual speed is 58.09 mph (93.48 km/h). Your speedometer reads 3.19% high versus actual speed.