L255/40R21
Standard MetricFactory Specs, Physical Dimensions & Compatible Vehicle Applications
Factory Spec Overview
The L255/40R21 tire size features an overall diameter of 29.03 inches, a section width of 10.0 inches (255mm), and rotates 695 times per mile. It is a standard factory tire fitment on 2+ vehicle models including Mercedes-Benz S63 E Performance AMG.
Physical Dimensions & Specs
Overall Diameter
29.03"
737.4 mmSection Width
255 mm
10.04" wideSidewall Height
4.02"
102.1 mm (40% aspect)Revolutions / Mile
695
Circumference: 91.21"Rim Diameter
21"
Wheel sizeRecommended Rim Width
6.4" - 8.9"
Optimal rim width rangeSpeedometer & Alternate Size Calculator
Testing an alternate size for your vehicle? Compare L255/40R21 against any proposed tire size below:
Popular Comparisons:
Tire 1 (Stock / Base)255/40R21
Overall Height:29.0"
Sidewall:4.0"
Revs/Mile:695
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+1.9%At 60 mph reading, actual speed is 61.1 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 20.4 mph | +0.4 mph |
| 30 mph | 30.6 mph | +0.6 mph |
| 45 mph | 45.8 mph | +0.8 mph |
| 60 mph | 61.1 mph | +1.1 mph |
| 75 mph | 76.4 mph | +1.4 mph |
| 90 mph | 91.7 mph | +1.7 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:+0.27" ground clearance
Vehicles That Fit L255/40R21 (2+ Models)
Factory standard and optional vehicle fitments utilizing L255/40R21 tires: