325/30R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 325/30R21 tire size features an overall diameter of 28.68 inches, a section width of 12.8 inches (325mm), and rotates 703 times per mile. It is a standard factory tire fitment on 15+ vehicle models including BMW X6 M, BMW X5 M.
Physical Dimensions & Specs
Overall Diameter
28.68"
728.5 mmSection Width
325 mm
12.80" wideSidewall Height
3.84"
97.5 mm (30% aspect)Revolutions / Mile
703
Circumference: 90.09"Rim Diameter
21"
Wheel sizeRecommended Rim Width
8.1" - 11.4"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 325/30R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)325/30R21
Overall Height:28.7"
Sidewall:3.8"
Revs/Mile:703
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+3.1%At 60 mph reading, actual speed is 61.9 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 20.6 mph | +0.6 mph |
| 30 mph | 30.9 mph | +0.9 mph |
| 45 mph | 46.4 mph | +1.4 mph |
| 60 mph | 61.9 mph | +1.9 mph |
| 75 mph | 77.3 mph | +2.3 mph |
| 90 mph | 92.8 mph | +2.8 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:+0.45" ground clearance
Vehicles That Fit 325/30R21 (15+ Models)
Factory standard and optional vehicle fitments utilizing 325/30R21 tires: