305/40R20 Standard Metric Factory Specs, Physical Dimensions & Compatible Vehicle Applications
The 305/40R20 tire size features an overall diameter of 29.61 inches, a section width of 12.0 inches (305mm), and rotates 681 times per mile. It is a standard factory tire fitment on 27+ vehicle models including Porsche Cayenne.
Physical Dimensions & Specs Overall Diameter 29.61"
752.1 mm Section Width 305 mm
12.01" wide Sidewall Height 4.8"
121.9 mm (40% aspect) Revolutions / Mile 681
Circumference: 93.01" Rim Diameter 20"
Wheel size Recommended Rim Width 7.6" - 10.7"
Optimal rim width range Where to Buy & Install 305/40R20 Tires Looking for 305/40R20 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 305/40R20 against any proposed tire size below:
Popular Comparisons: Standard Crossover Upgrade (225/65R17 → 245/60R18) Truck Off-Road Fitment (265/70R17 → 285/70R17) Sport Compact Plus-One (205/55R16 → 225/45R17) Performance Sedan Stance (245/45R18 → 265/35R19)
Visual Tire & Wheel Comparison Tire 1 29.6" Height Tire 2 29.6" Height
Speedometer Variance -0.1% At 60 mph reading, actual speed is 59.9 mph
Indicated Actual Speed Diff 20 mph 20.0 mph -0.0 mph 30 mph 30.0 mph -0.0 mph 45 mph 45.0 mph -0.0 mph 60 mph 59.9 mph -0.1 mph 75 mph 74.9 mph -0.1 mph 90 mph 89.9 mph -0.1 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: -0.02" lower ground clearance
Vehicles That Fit 305/40R20 (27+ Models) Factory standard and optional vehicle fitments utilizing 305/40R20 tires:
Year Make & Model Trim / Variant Lookup Specs 2019 Porsche Cayenne Base View 2019 Cayenne › 2019 Porsche Cayenne S View 2019 Cayenne › 2019 Porsche Cayenne E-Hybrid View 2019 Cayenne › 2020 Porsche Cayenne Base, 4D Utility Wagon View 2020 Cayenne › 2020 Porsche Cayenne Base, 4D Utility Coupe View 2020 Cayenne › 2020 Porsche Cayenne E-Hybrid, 4D Utility Wagon View 2020 Cayenne › 2020 Porsche Cayenne E-Hybrid, 4D Utility Coupe View 2020 Cayenne › 2020 Porsche Cayenne S, 4D Utility Coupe View 2020 Cayenne › 2020 Porsche Cayenne S, 4D Utility Wagon View 2020 Cayenne › 2021 Porsche Cayenne Base, 4D Utility Coupe View 2021 Cayenne › 2021 Porsche Cayenne Base, 4D Utility Wagon View 2021 Cayenne › 2021 Porsche Cayenne E-Hybrid, 4D Utility Coupe View 2021 Cayenne › 2021 Porsche Cayenne E-Hybrid, 4D Utility Wagon View 2021 Cayenne › 2021 Porsche Cayenne S, 4D Utility Wagon View 2021 Cayenne › 2021 Porsche Cayenne S, 4D Utility Coupe View 2021 Cayenne › 2022 Porsche Cayenne Base, 4D Utility Coupe View 2022 Cayenne › 2022 Porsche Cayenne Base, 4D Utility Wagon View 2022 Cayenne › 2022 Porsche Cayenne E-Hybrid, 4D Utility Coupe View 2022 Cayenne › 2022 Porsche Cayenne E-Hybrid, 4D Utility Wagon View 2022 Cayenne › 2022 Porsche Cayenne S, 4D Utility Coupe View 2022 Cayenne › 2022 Porsche Cayenne S, 4D Utility Wagon View 2022 Cayenne › 2023 Porsche Cayenne Base, 4D Utility Coupe View 2023 Cayenne › 2023 Porsche Cayenne Base, 4D Utility Wagon View 2023 Cayenne › 2023 Porsche Cayenne E-Hybrid, 4D Utility Coupe View 2023 Cayenne › 2023 Porsche Cayenne E-Hybrid, 4D Utility Wagon View 2023 Cayenne › 2023 Porsche Cayenne S, 4D Utility Coupe View 2023 Cayenne › 2023 Porsche Cayenne S, 4D Utility Wagon View 2023 Cayenne ›