The 2013 Audi S8 sits at the sharp end of Audi’s full-size performance sedan lineup, blending executive-car refinement with the kind of speed and chassis control that demands serious tire fitment. On this model, the tire decision centers on two 21-inch radial sizes tied to specific configurations: 275/35R21 and 265/35R21. That means the first step is identifying whether the car is set up as the Summer Tires version or the Base model before choosing a replacement. From there, the focus shifts to maintaining the intended stance, handling balance, and clearance on a sedan whose performance character is heavily influenced by the tires it rides on.
Which Tire Size Is Right for The 2013 Audi S8
The 2013 Audi S8 uses two primary tire sizes, and both are radial tires built for 21-inch wheels. The correct choice depends on the exact configuration, since the Summer Tires version uses a different size than the Base model. Before selecting a tire, confirm the sub-model and verify that the wheels currently on the car are still the intended 21-inch setup, especially if the vehicle has been modified or fitted with alternate wheel packages.
275/35R21 is a modern metric radial size in which 275 identifies the section width in millimeters, 35 is the aspect ratio, R indicates radial construction, and 21 is the wheel diameter in inches. On the 2013 Audi S8, this size belongs to the Summer Tires configuration and reflects a low-profile, large-diameter performance fitment. Its dimensions support the look and road behavior expected from a high-performance luxury sedan. Choose this size only after confirming that the car is the Summer Tires version and that wheel width, suspension condition, and body clearance remain appropriate for the current setup.
265/35R21 is also a modern metric radial size, with 265 representing section width in millimeters, 35 showing the aspect ratio, and 21 marking the wheel diameter. On the 2013 Audi S8, this is the primary fitment for the Base model, making it a specific configuration-based choice rather than an interchangeable alternative to every S8 setup. Its slightly narrower section compared with 275/35R21 still keeps the same 21-inch wheel format and low-profile performance character. This is the size to evaluate when the car is a Base model and the wheel package remains true to that fitment.
Sub-model fitment matters on the 2013 Audi S8 because the covered configurations do not share the same tire size. The first step is confirming whether the car is the Summer Tires version or the Base model, since that determines which 21-inch radial size belongs on it.
1
2013 Audi S8 (Summer Tires)
The 2013 Audi S8 Summer Tires configuration uses the 275/35R21 radial size. That makes tire selection less about choosing between multiple primary fitments and more about confirming the car still has the correct 21-inch wheel setup and selecting a replacement that suits its performance-oriented use.
The 2013 Audi S8 Base uses the 265/35R21 radial tire size. Tire selection here starts with keeping that configuration-specific fitment in place, then checking that the wheel diameter, wheel width, and any suspension or wheel changes have not altered the space available around the tire.
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
These FAQs focus on the 2013 Audi S8’s two 21-inch tire sizes, how sub-model fitment changes the answer, and what to inspect before replacing tires on a high-performance luxury sedan.
Tire Size & Fitment
What tire size fits a 2013 Audi S8?
The 2013 Audi S8 uses two different tire sizes depending on configuration. The Summer Tires version uses 275/35R21, while the Base model uses 265/35R21. Both are radial tires built for 21-inch wheels, so the correct size depends on the exact sub-model rather than on the model name alone.
That means the first job is confirming which S8 configuration the car actually has, then checking the wheel size currently on the vehicle. If aftermarket wheels, suspension changes, or a previous tire substitution are involved, compare the current setup carefully before ordering replacement tires in either 275/35R21 or 265/35R21.
What size rim does a 2013 Audi S8 use?
Both tire sizes used on the 2013 Audi S8 are built for a 21-inch rim. That applies to the 275/35R21 fitment used on the Summer Tires version and the 265/35R21 fitment used on the Base model. The shared wheel diameter simplifies part of the decision, but it does not make the two tire sizes the same fitment.
A 21-inch rim is only one part of the picture, because wheel width and the car’s actual setup still matter. Before replacing tires, confirm that the vehicle still carries the intended 21-inch wheels and inspect for any changes in wheel width, offset, ride height, or clearance that could affect how either size sits and operates.
Do all 2013 Audi S8 sub-models use the same tire size?
No, the covered 2013 Audi S8 sub-models do not use the same tire size. The Summer Tires version uses 275/35R21, while the Base model uses 265/35R21. Both are radial 21-inch fitments, but the difference in section width means they should be treated as distinct sub-model-specific sizes.
That distinction matters when replacing a worn set or correcting a mismatch from a previous owner. Start by identifying the exact sub-model, then verify the wheels currently installed on the car. On a performance sedan like the S8, even a seemingly small size change can affect clearance, visual stance, and how closely the replacement matches the intended setup.
Choosing the Right Tire
What should I consider when choosing a 2013 Audi S8 tire?
Start with the correct sub-model-specific size. A 2013 Audi S8 Summer Tires configuration uses 275/35R21, while a 2013 Audi S8 Base uses 265/35R21, and both require 21-inch radial fitment. On this vehicle, choosing the right tire begins with matching the size to the configuration rather than treating every S8 as identical.
After confirming size, look at the car’s current wheel setup and intended use. A low-profile 21-inch tire should be selected with attention to wheel width, clearance, suspension condition, and whether the car is kept near original specification. If the S8 has been modified, the actual wheel and body fit should be checked before settling on a replacement.
How do I choose between the available 21-inch tires for a 2013 Audi S8?
The first filter is simple: use 275/35R21 for the Summer Tires version and 265/35R21 for the Base model. Once the correct size is established, the remaining decision is about finding a tire that matches the car’s current wheel setup and the kind of road use expected from a modern high-performance luxury sedan.
Low-profile 21-inch fitments leave less margin for error than more forgiving vintage sizes, so the details matter. Compare the replacement against the actual wheels on the car, inspect for past changes in ride height or suspension parts, and keep front-to-body and steering clearance in mind before moving ahead with a new set.
What rim-fitment details matter when choosing 2013 Audi S8 tires?
The key rim-fitment detail is that both 2013 Audi S8 tire sizes use a 21-inch wheel diameter, but the car still relies on the correct tire width for the specific configuration. A Summer Tires car uses 275/35R21, while a Base car uses 265/35R21, so wheel diameter alone does not settle the fitment question.
Wheel width, offset, and any non-original wheel changes should be checked before replacing tires. Those factors influence how the tire sits on the rim and how much room remains at the fender, suspension, and steering components. On a sedan with this kind of performance envelope, confirming the actual wheel setup helps avoid choosing a size that only looks correct on paper.
Restoration & Appearance
Does correct tire fitment matter for a 2013 Audi S8 restoration or preservation project?
Yes, correct tire fitment matters on a 2013 Audi S8 because the car uses configuration-specific 21-inch sizes rather than one universal fitment. A preservation-minded approach starts by keeping the Summer Tires version on 275/35R21 and the Base model on 265/35R21, which helps maintain the intended look and proportions of each setup.
Appearance on a modern performance sedan is closely tied to section width and sidewall profile, especially with large-diameter wheels. Even when the rim diameter stays at 21 inches, switching to a different width can change the car’s visual stance. Owners aiming for an authentic presentation should verify the original configuration of the specific car before selecting replacements.
Which tire fitment should I keep for a period-appropriate 2013 Audi S8?
A period-appropriate approach means retaining the tire size that matches the car’s actual 2013 Audi S8 configuration. That means 275/35R21 for the Summer Tires version and 265/35R21 for the Base model, both in radial construction on 21-inch wheels. Keeping the original fitment pattern preserves the visual balance intended for that version of the S8.
Because this is a newer collector-era vehicle, preserving the right proportions is often more important than chasing a dramatic change in size. Before replacing tires, confirm that the wheels currently installed are the correct diameter and width for the car’s setup. That check is especially worthwhile if the vehicle has passed through multiple owners or received cosmetic modifications.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2013 Audi S8?
Yes, modifications can affect tire fitment on a 2013 Audi S8, even when the car still appears to use the correct 21-inch wheel diameter. Changes such as aftermarket wheels, different wheel widths or offsets, lowered suspension, or body alterations can influence whether 275/35R21 or 265/35R21 sits correctly within the available space.
That is especially important on a low-profile performance fitment where clearances are tighter and visual changes can be subtle. If the S8 has any non-original hardware, inspect steering lock clearance, fender room, and suspension travel before replacing tires. Confirming the actual wheel and chassis setup helps prevent choosing a tire that matches the label but not the car.
What should I inspect before driving a 2013 Audi S8 on new tires?
Before driving a 2013 Audi S8 on new tires, inspect the wheel condition, verify the installed tire size matches the car’s sub-model, and make sure the tires are seated properly on the 21-inch rims. It is also wise to check inflation pressure, valve condition, and whether the suspension or alignment shows any obvious wear.
A quick road-use inspection should also include looking for rubbing points, unusual tread contact, or signs that the car’s ride height or wheel setup has changed over time. On a performance sedan with short sidewalls, alignment and clearance issues show up quickly. Taking a few minutes to confirm those basics helps the new tires perform as intended.
How often should tires on a 2013 Audi S8 be inspected?
Tires on a 2013 Audi S8 should be inspected regularly, with extra attention before longer drives and any time the car has been stored for an extended period. A close check should include tread wear, sidewall condition, cuts, bulges, and air loss. Because this model uses low-profile 21-inch tires, small problems can become noticeable quickly.
Inspection is also a good time to confirm that the car still carries the proper size for its configuration, especially on vehicles that may have had wheel changes. Uneven wear can point to alignment or suspension issues, while sidewall damage deserves immediate attention. Consistent inspection is one of the simplest ways to protect both fitment and road manners.
