315/40R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
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 rangeWhere to Buy & Install 315/40R21 Tires
Looking for 315/40R21 tires? Skip hauling tires in your car—choose direct delivery to a local certified shop or doorstep delivery:
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Speedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare 315/40R21 against any proposed tire size below:
Visual Tire & Wheel Comparison
Speedometer Variance
| 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
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Vehicles That Fit 315/40R21 (26+ Models)
Factory standard and optional vehicle fitments utilizing 315/40R21 tires: