The 2020 Audi S8 sits at the top of Audi’s full-size performance sedan range, blending understated executive luxury with the speed and chassis capability expected from a modern S car. Buyers looking at this exact model are usually balancing sharp road manners, high-speed stability, and the right visual stance on a large-diameter wheel package. The 2020 Audi S8 uses radial tire fitments in 265/40R20, 265/35R21, and 275/35R21, so the first step is confirming which wheel setup is actually on the car. Once that is settled, the decision shifts to selecting the right size, load-appropriate construction, and fitment that suits factory-style driving character or a modified setup.
Which Tire Size Is Right for The 2020 Audi S8
The 2020 Audi S8 uses three primary tire sizes, and the correct choice depends first on the wheel package installed on the car. Two sizes fit 21-inch wheels and one fits a 20-inch wheel, so confirming actual rim diameter is more important than assuming every S8 uses the same setup. Once the wheel size is verified, the real decision becomes choosing the proper metric radial size for clearance, handling balance, and the car’s current wheel and suspension configuration.
265/35R21 is a metric radial size where 265 identifies the nominal section width in millimeters, 35 is the aspect ratio, R indicates radial construction, and 21 is the wheel diameter in inches. On the 2020 Audi S8, this size belongs to a modern low-profile performance fitment built around a large 21-inch wheel. Its dimensions support the sharp, contemporary stance expected from this sedan, while still requiring close attention to wheel width, offset, and overall clearance. This is an important size to confirm when the car is equipped with 21-inch wheels and a lower-profile tire presentation.
265/40R20 is a metric radial size with a 265-millimeter nominal section width, a 40-series aspect ratio, and a 20-inch rim diameter. For the 2020 Audi S8, it represents the 20-inch wheel fitment and carries nearly the same overall diameter as the 21-inch alternatives while using a taller sidewall profile. That makes it a distinct choice tied to wheel diameter rather than a minor variation within the same setup. Buyers should focus on this size when the car is on 20-inch wheels or when verifying whether an aftermarket wheel package changed the original fitment direction.
275/35R21 is a metric radial size where 275 gives the nominal section width in millimeters, 35 defines the aspect ratio, and 21 identifies the wheel diameter. Compared with the 265-section 21-inch size, this fitment uses a wider tread section and a slightly larger overall diameter, making it a separate primary S8 fitment rather than a simple alternate description of the same tire. That difference matters when evaluating wheel width, inner clearance, and fender room on a car that may already have wheel or suspension changes. This size should be matched carefully to the exact 21-inch setup on the vehicle.
The 2020 Audi S8 Base is the covered sub-model, but tire fitment is not limited to one size. Because the Base can use 20-inch and 21-inch wheel packages, confirming the exact wheel and tire setup on the car is still the key step before selecting a replacement.
1
2020 Audi S8 Base
The 2020 Audi S8 Base uses all three primary fitments associated with this model, including one 20-inch radial size and two 21-inch radial sizes. That means tire selection starts with confirming the wheel diameter and then matching the exact metric size already fitted, especially if the car has aftermarket wheels or suspension changes.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Frequently Asked Questions
Tire questions for the 2020 Audi S8 usually come down to identifying the correct metric size, confirming 20-inch versus 21-inch wheel fitment, and checking how wheel or suspension changes may affect clearance. The answers below focus on exact size meaning, selection, and practical road-use checks.
Tire Size & Fitment
What tire size fits a 2020 Audi S8?
The 2020 Audi S8 uses three primary radial tire sizes: 265/40R20, 265/35R21, and 275/35R21. Those sizes are all associated with the S8 Base, so the correct choice is tied to the wheel setup on the individual car rather than to a different named trim within the model line.
The most important first step is checking whether the car has 20-inch or 21-inch wheels, then matching the exact size already intended for that setup. A 20-inch fitment and a 21-inch fitment are not interchangeable simply because their overall diameters are close, and any aftermarket wheel or suspension change should be verified before replacement.
What size rim does a 2020 Audi S8 use?
The 2020 Audi S8 uses either a 20-inch or 21-inch rim, depending on which primary tire size is on the car. The 265/40R20 fits a 20-inch wheel, while both 265/35R21 and 275/35R21 fit 21-inch wheels.
That distinction matters because rim diameter is the first fitment checkpoint on this model. Measuring the existing wheel or reading the size stamped on the tire sidewall will usually confirm the correct diameter quickly, and it is especially important on an S8 that may already have a non-original wheel package installed.
Why does the 2020 Audi S8 have more than one tire size?
The 2020 Audi S8 has more than one tire size because it can be configured with different wheel diameters and 21-inch fitments that are not identical in section width. The three primary sizes are 265/40R20, 265/35R21, and 275/35R21, all in radial construction.
That means the right tire is determined by the exact wheels on the car, not by model name alone. It is smart to confirm the size currently mounted, then compare wheel width, offset, and available clearance before changing to another listed size, particularly on a performance sedan where even small differences can affect fitment.
Choosing the Right Tire
What should I consider when choosing a 2020 Audi S8 tire?
Start with the exact size already matched to the car’s wheel diameter: 265/40R20, 265/35R21, or 275/35R21. On a 2020 Audi S8, choosing correctly is less about broad brand comparison and more about matching the proper metric radial fitment to the vehicle’s actual wheel package and intended road use.
Beyond the size itself, check wheel width, load suitability, and clearance around the suspension and fenders. An S8 with factory-style wheels may simply need the same size replaced, but a car with aftermarket wheels, spacers, or ride-height changes should have the entire setup reviewed before another tire is selected.
How do I choose between the available 21-inch tires for a 2020 Audi S8?
The two 21-inch primary sizes for the 2020 Audi S8 are 265/35R21 and 275/35R21. Even though both fit a 21-inch wheel, they are different fitments, with the 275 size using a wider nominal section width and a slightly different overall dimension.
Choosing between them should begin with the exact wheel and tire specification already on the car. A wider 21-inch size can affect clearance, especially near the inner suspension or outer fender, so the selection should follow the wheel setup that the car is actually using rather than treating both 21-inch options as universally interchangeable.
What rim-fitment details matter when choosing tires for a 2020 Audi S8?
Rim diameter is the first detail to verify on a 2020 Audi S8 because the car uses both 20-inch and 21-inch tire fitments. The tire must match the wheel diameter exactly, and the two 21-inch sizes also need to be matched carefully to the wheel package already installed.
Wheel width and offset matter next, especially if the car no longer has its original wheel setup. A tire that is correct by size code still needs proper support on the wheel and enough running room through steering travel and suspension movement, so those checks are worthwhile before settling on a replacement.
Restoration & Appearance
Does correct tire fitment matter for a 2020 Audi S8 restoration or preservation project?
Yes. Even on a relatively modern performance sedan like the 2020 Audi S8, correct tire fitment matters if the goal is to preserve the car’s intended stance, handling balance, and overall presentation. Using the proper 20-inch or 21-inch metric radial size keeps the visual proportions aligned with the wheel package fitted to the car.
A preservation-minded owner should confirm the exact size and wheel setup before replacing tires, especially if the car was acquired used. If appearance originality matters, comparing the current setup with window-sticker records, service history, or marque-specific references can help determine whether the wheels and tires still reflect the car’s original configuration.
How does tire size affect the appearance of a 2020 Audi S8?
Tire size has a visible effect on the 2020 Audi S8 because the car uses low-profile metric radials on large 20-inch or 21-inch wheels. The difference between 265/40R20, 265/35R21, and 275/35R21 changes sidewall height, wheel-to-tire proportion, and the visual width of the contact patch.
That makes size choice important for owners who want the car to keep a factory-style look rather than simply filling the wheel opening. Matching the existing wheel package preserves the intended presentation more closely, while moving to another listed size should be approached carefully and only after the wheel dimensions and clearances are confirmed.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2020 Audi S8?
Yes. Modifications can change tire fitment on a 2020 Audi S8 even when the size itself is one of the model’s primary fitments. Aftermarket wheels, spacers, lowered suspension, alignment changes, or brake upgrades can all alter the space available for a 265/40R20, 265/35R21, or 275/35R21 tire.
That is why replacement should not rely on model name alone when the car has been changed from stock. Checking wheel width, offset, inner clearance, and fender room helps prevent rubbing or setup conflicts, and it is particularly important when moving between the two different 21-inch sizes on an already modified chassis.
What should I inspect before driving a 2020 Audi S8 on new tires?
Inspect the wheel and tire size match first, then verify proper inflation, even bead seating, valve condition, and sufficient clearance at full steering lock. On a 2020 Audi S8, it is also wise to check for any signs that the wheel setup, suspension height, or alignment has changed from standard.
A short, careful road test should follow, with attention to vibration, rubbing, pull, or warning messages. Modern performance sedans place high demands on tires, so catching a mounting issue early matters, and a recheck after the first miles can confirm that pressures remain stable and no clearance problem appears under real movement.
What should I check before a longer drive in a 2020 Audi S8?
Before a longer drive, confirm that the 2020 Audi S8 is riding on the correct tire size for its wheels and that all four tires are in sound condition. Look for uneven wear, cuts, bulges, punctures, or cracking, and make sure pressures are set consistently when the tires are cold.
It also helps to review wheel condition and basic suspension behavior before putting highway miles on a high-performance sedan. A tire that looks acceptable in the garage may reveal vibration or clearance issues at speed, so checking balance, alignment behavior, and any recent wheel or suspension changes is a sensible final step.
