255/35R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 255/35R21 tire size features an overall diameter of 28.03 inches, a section width of 10.0 inches (255mm), and rotates 720 times per mile. It is a standard factory tire fitment on 42+ vehicle models including Audi S6, Audi S7.
Physical Dimensions & Specs
Overall Diameter
28.03"
712.0 mmSection Width
255 mm
10.04" wideSidewall Height
3.51"
89.2 mm (35% aspect)Revolutions / Mile
720
Circumference: 88.05"Rim Diameter
21"
Wheel sizeRecommended Rim Width
6.4" - 8.9"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 255/35R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)255/35R21
Overall Height:28.0"
Sidewall:3.5"
Revs/Mile:720
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+5.5%At 60 mph reading, actual speed is 63.3 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 21.1 mph | +1.1 mph |
| 30 mph | 31.7 mph | +1.7 mph |
| 45 mph | 47.5 mph | +2.5 mph |
| 60 mph | 63.3 mph | +3.3 mph |
| 75 mph | 79.1 mph | +4.1 mph |
| 90 mph | 95.0 mph | +5.0 mph |
Fender & Suspension Clearance
Fitment Status: MODERATE RISK
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Inner Strut Space:7.7mm LESS clearance
Outer Fender Push:Extends 17.7mm further out
Ride Height Delta:+0.77" ground clearance
Vehicles That Fit 255/35R21 (42+ Models)
Factory standard and optional vehicle fitments utilizing 255/35R21 tires: