315/40R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The 315/40R21 tire size features an overall diameter of 30.92 inches, a section width of 12.4 inches (315mm), and rotates 652 times per mile. It is a standard factory tire fitment on 26+ vehicle models including Mercedes-Benz GLE450 AMG, Mercedes-Benz GLE43 AMG.
Physical Dimensions & Specs
Overall Diameter
30.92"
785.4 mmSection Width
315 mm
12.40" wideSidewall Height
4.96"
126.0 mm (40% aspect)Revolutions / Mile
652
Circumference: 97.14"Rim Diameter
21"
Wheel sizeRecommended Rim Width
7.9" - 11"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 315/40R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)315/40R21
Overall Height:30.9"
Sidewall:5.0"
Revs/Mile:652
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
-4.4%At 60 mph reading, actual speed is 57.4 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 19.1 mph | -0.9 mph |
| 30 mph | 28.7 mph | -1.3 mph |
| 45 mph | 43.0 mph | -2.0 mph |
| 60 mph | 57.4 mph | -2.6 mph |
| 75 mph | 71.7 mph | -3.3 mph |
| 90 mph | 86.1 mph | -3.9 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:-0.67" lower ground clearance
Vehicles That Fit 315/40R21 (26+ Models)
Factory standard and optional vehicle fitments utilizing 315/40R21 tires: