285/30R18
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 285/30R18 tire size features an overall diameter of 24.73 inches, a section width of 11.2 inches (285mm), and rotates 815 times per mile. It is a standard factory tire fitment on 7+ vehicle models including Porsche 911.
Physical Dimensions & Specs
Overall Diameter
24.73"
628.1 mmSection Width
285 mm
11.22" wideSidewall Height
3.37"
85.6 mm (30% aspect)Revolutions / Mile
815
Circumference: 77.7"Rim Diameter
18"
Wheel sizeRecommended Rim Width
7.1" - 10"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 285/30R18 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)285/30R18
Overall Height:24.7"
Sidewall:3.4"
Revs/Mile:815
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+19.6%At 60 mph reading, actual speed is 71.7 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 23.9 mph | +3.9 mph |
| 30 mph | 35.9 mph | +5.9 mph |
| 45 mph | 53.8 mph | +8.8 mph |
| 60 mph | 71.7 mph | +11.7 mph |
| 75 mph | 89.7 mph | +14.7 mph |
| 90 mph | 107.6 mph | +17.6 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:+2.42" ground clearance
Vehicles That Fit 285/30R18 (7+ Models)
Factory standard and optional vehicle fitments utilizing 285/30R18 tires: