The 2004 Audi S4 sits at an interesting point in early-2000s performance sedan history, blending Audi’s compact executive footprint with serious all-wheel-drive capability and understated styling. Whether in Base, Avant, or Cabriolet form, it appeals to owners who want modern German performance with real collector-era character. Tire fitment is straightforward, with a single 235/40R18 radial size on an 18-inch rim across the covered sub-models. That simplicity shifts the decision toward choosing the right performance-oriented radial within the size, including brand and tire-series differences. For a stock or lightly modified S4, the key is matching the correct size while confirming wheel width, condition, and intended road use.
Which Tire Size Is Right for The 2004 Audi S4
The 2004 Audi S4 uses one primary tire size: 235/40R18, a modern metric radial fitted to an 18-inch rim. That same fitment carries across the covered Avant, Base, and Cabriolet sub-models, so the main decision is not choosing between multiple factory sizes but selecting the right tire within that size for the car’s wheel setup, driving style, and overall condition.
A 235/40R18 size uses a 235-millimeter nominal section width, a 40-series aspect ratio, radial construction, and an 18-inch rim diameter. On the 2004 Audi S4, this is the modern radial fitment that supports the car’s performance-oriented character and keeps sizing aligned with its original wheel diameter. Available choices in this size include BFGoodrich and Nitto products, all in Blackwall form, with several performance-focused tire series. The practical choice comes down to staying with the correct dimensions while comparing rim-width compatibility, load figures where stated, and the type of road use the car will actually see.
Fitment is straightforward across the covered 2004 Audi S4 sub-models, with the same 235/40R18 radial size used throughout. Checking the exact sub-model still matters when confirming the vehicle’s current wheel and tire setup, especially on cars that may have been modified over time.
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2004 Audi S4 Avant
The 2004 Audi S4 Avant uses the same 235/40R18 radial fitment as the other covered S4 versions. That makes tire selection more about comparing available performance-oriented products in the correct size and verifying that the wagon still retains the proper 18-inch wheel setup.
The 2004 Audi S4 Base also uses 235/40R18 radial tires on an 18-inch rim. For most buyers, the focus is choosing among the available Blackwall performance radials while checking wheel width, suspension condition, and any aftermarket changes before replacing tires.
The 2004 Audi S4 Cabriolet shares the same 235/40R18 radial tire size used across the covered S4 range. Tire choice centers on selecting the right product within that size and confirming that the convertible still has the correct wheel fitment and adequate clearance at full steering lock.
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.
Best 2004 Audi S4 Tires for Sale
Available 235/40R18 options for the 2004 Audi S4 focus on modern radial performance tires from BFGoodrich and Nitto. The product grid lets you compare Blackwall offerings across several tire series, along with rim-width compatibility, weight, and stated load figures where available.
These FAQs for the 2004 Audi S4 focus on the 235/40R18 fitment, 18-inch rim compatibility, product-selection differences, and the inspection checks that matter before putting a performance-oriented S4 back on the road.
Tire Size & Fitment
What tire size fits a 2004 Audi S4?
The 2004 Audi S4 uses a 235/40R18 radial tire. That fitment applies across the covered S4 Base, Avant, and Cabriolet sub-models, making tire size selection unusually straightforward for this vehicle compared with cars that split fitment by trim or package.
The practical step is confirming that the car still has the correct 18-inch wheels and has not been changed to a different wheel diameter or aftermarket setup. Once the wheel setup is verified, the decision shifts to comparing tires within 235/40R18 by brand, tire series, rim-width compatibility, and other product details that suit how the S4 is driven.
What size rim does a 2004 Audi S4 use?
The primary tire fitment for the 2004 Audi S4 is built around an 18-inch rim diameter. That matches the 235/40R18 tire size used on the covered sub-models and sets the basic wheel diameter that matters when choosing replacement tires.
Rim diameter is only part of the fitment picture, so it is still worth checking the actual wheel width before buying a tire. The available 235/40R18 products call for widths in the 8.0 to 9.5 inch range, which is helpful when confirming compatibility on a stock S4 or one that may have received replacement wheels over the years.
Do all 2004 Audi S4 sub-models use the same tire size?
Yes. The covered 2004 Audi S4 sub-models share the same primary tire size: 235/40R18 radial. That includes the Base, Avant, and Cabriolet, so there is no split here between body styles in the main fitment size.
Even with shared sizing, it is smart to inspect the car rather than assume every S4 still wears its original wheel package. A previous owner may have changed wheels, altered suspension height, or fitted a different tire size, and those changes should be checked before replacing tires so the new set matches the vehicle’s actual setup and clearance needs.
Choosing the Right Tire
What should I consider when choosing a 235/40R18 tire for a 2004 Audi S4?
Start with the correct 235/40R18 size and confirm that the tire matches the S4’s 18-inch wheel setup. From there, compare construction, rim-width range, stated load figures where available, and the product’s overall character, since the available choices in this size are all modern radial performance-oriented tires.
A useful next step is thinking about how the car is actually used. An S4 driven mainly on fair-weather roads may call for a different product emphasis than one used more broadly for regular street driving, and wheel width, suspension condition, and alignment should be checked so the selected tire can work as intended.
What brands offer tires for the 2004 Audi S4?
Tires in the 2004 Audi S4’s 235/40R18 size are available from BFGoodrich and Nitto. BFGoodrich appears across several performance-oriented series in this fitment, while Nitto is also offered in the same size and Blackwall sidewall style.
Brand choice should be part of a broader comparison rather than the only factor. It helps to look at the tire series, rim-width specification, weight, and any stated load capacity along with how the S4 is driven, especially since a performance sedan like this can be sensitive to mismatched tire characteristics or wheel setup changes.
What tire series are available for the 2004 Audi S4?
The 2004 Audi S4’s 235/40R18 fitment is offered in several tire series, including BFGoodrich g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, and Nitto NT555 G2. These choices give the buyer several ways to stay with the correct size while comparing product character.
Looking at tire series is useful because it helps separate one 235/40R18 option from another without changing the vehicle’s fitment. The right comparison includes wheel-width compatibility, any stated load information, and the kind of use expected from the car, whether that means occasional enthusiast driving or more regular street miles.
Restoration & Appearance
Which tire should I choose for a period-style 2004 Audi S4?
A period-style approach for a 2004 Audi S4 starts with keeping the correct 235/40R18 size and 18-inch wheel diameter. Since the available products in this fitment are modern radial tires with Blackwall sidewalls, the visual direction remains consistent with the understated performance look that suits an early-2000s Audi S-car.
Appearance-minded buyers should focus on preserving the right proportions rather than chasing a vintage-style treatment that does not match the car’s era. On a vehicle like this, wheel design, ride height, and tire profile all affect the finished look, so confirming that the car remains close to its intended stance is just as important as the tire brand.
Does correct tire fitment matter for a 2004 Audi S4 restoration?
Yes, correct tire fitment matters because the 2004 Audi S4’s stance, wheel fill, and overall presentation depend heavily on staying with the proper 235/40R18 sizing. Even on a modern-era collector car, the wrong profile or wheel diameter can change the car’s appearance as much as it changes its road manners.
Fitment accuracy also helps keep a restoration grounded in the car’s original visual character. If exact historical presentation is important, it is worth checking marque-specific references and the car’s existing wheel setup before purchase, especially on examples that may have passed through multiple owners with different preferences for wheels, suspension, or tire brand.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2004 Audi S4?
Yes. Even though the primary fitment is 235/40R18 on an 18-inch rim, modifications can change whether that size still works as intended on a specific 2004 Audi S4. Aftermarket wheels, different wheel widths, altered offsets, suspension changes, or lowered ride height can all affect clearance and overall compatibility.
A modified S4 should be checked at the wheel, not just by model year. Tire-to-fender space, inner clearance, steering travel, and the wheel’s actual dimensions all matter before replacing tires, and those checks are especially important on performance cars where small setup changes can make a noticeable difference in fitment behavior.
What should I inspect before driving a 2004 Audi S4 on new tires?
Before road use, inspect the wheels for damage, confirm the tires are mounted in the correct 235/40R18 size, and check inflation pressure, tread condition, and overall installation quality. It is also wise to look over suspension and steering components, since worn parts can affect how a freshly fitted tire behaves on the car.
A short visual check of sidewalls and wheel clearances is worthwhile after installation, especially at full steering lock. On a 2004 Audi S4, alignment condition also deserves attention because uneven wear or poor tracking can quickly undermine a new set of performance-oriented tires and make the car feel less precise than it should.
How often should tires on a 2004 Audi S4 be inspected?
Tires on a 2004 Audi S4 should be inspected regularly, not just when tread appears low. A quick check for air loss, uneven wear, cuts, bulges, and sidewall cracking is smart before routine driving, and a more careful inspection is worthwhile before longer trips or after the car has been stored for extended periods.
Performance-oriented cars can be more sensitive to tire condition than a basic commuter, so routine inspection helps catch problems before they affect ride quality or handling. It also pays to verify pressure and look for signs of age-related deterioration, particularly on lower-mile collector examples that may spend long stretches parked between drives.
