285/30R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 285/30R21 tire size features an overall diameter of 27.73 inches, a section width of 11.2 inches (285mm), and rotates 727 times per mile. It is a standard factory tire fitment on 26+ vehicle models including BMW Alpina.
Physical Dimensions & Specs
Overall Diameter
27.73"
704.3 mmSection Width
285 mm
11.22" wideSidewall Height
3.37"
85.6 mm (30% aspect)Revolutions / Mile
727
Circumference: 87.12"Rim Diameter
21"
Wheel sizeRecommended Rim Width
7.1" - 10"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 285/30R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)285/30R21
Overall Height:27.7"
Sidewall:3.4"
Revs/Mile:727
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+6.6%At 60 mph reading, actual speed is 64.0 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 21.3 mph | +1.3 mph |
| 30 mph | 32.0 mph | +2.0 mph |
| 45 mph | 48.0 mph | +3.0 mph |
| 60 mph | 64.0 mph | +4.0 mph |
| 75 mph | 80.0 mph | +5.0 mph |
| 90 mph | 96.0 mph | +6.0 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:+0.92" ground clearance
Vehicles That Fit 285/30R21 (26+ Models)
Factory standard and optional vehicle fitments utilizing 285/30R21 tires: