How Much Oil a 2018 Audi S6 Takes

The 2018 Audi S6 typically takes about 7.9 quarts (7.5 liters) of engine oil when changing oil and filter, using VW-approved synthetic oil of the correct specification. However, the exact capacity can vary slightly depending on the specific engine code and regional model, so it is essential to confirm with the owner’s manual or a dealer.

Understanding the 2018 Audi S6 Oil Capacity

The 2018 Audi S6 is equipped with a 4.0-liter twin-turbocharged V8 (commonly the 4.0 TFSI), and like most high-performance engines, it requires a relatively large volume of oil to ensure proper lubrication and cooling. In practice, owners and technicians generally work with an oil-fill amount of about 7.9 quarts (7.5 liters) when performing a standard oil and filter change.

Official Capacity and Specification

Audi publishes oil capacities and specifications in the owner’s manual and service documentation. For the 2018 S6 4.0 TFSI V8, the commonly referenced service-fill capacity (oil change with filter) is roughly:

The following list outlines the typical oil quantity and specification for a 2018 Audi S6, based on commonly cited service data and Audi’s own oil standards.

• Approximate oil capacity with filter: about 7.9 US quarts (7.5 liters)
• Oil type: Fully synthetic engine oil
• Oil viscosity (common in North America): SAE 5W-40 or 0W-40 (check climate and manual)
• Oil standard: Must meet Audi/VW spec (typically VW 502 00, or regionally recommended equivalent)
• Filter: OEM-quality oil filter designed for the 4.0 TFSI V8

Treated as a guideline, these figures help owners and service shops select the correct quantity and grade of oil, but final confirmation should always come from the vehicle’s documentation and local Audi recommendations.

Why the Capacity Matters

High-output engines like the S6’s twin-turbo 4.0 TFSI place significant thermal and mechanical stress on lubricant. Using the correct amount of oil is critical not only to protect internal components, but also to maintain proper oil pressure, reduce coking in turbochargers, and support long-term reliability.

Risks of Overfilling or Underfilling

Because the Audi S6 uses a performance-oriented V8 with tight tolerances and turbochargers, small errors in oil level can have outsized consequences. Underfilling deprives engine parts of lubrication, while overfilling may cause foaming, crankshaft splashing, and potential seal issues.

The following list explains the key risks associated with incorrect oil levels in a 2018 Audi S6.

• Underfilling: Can lead to low oil pressure, increased wear on bearings, camshafts, and turbochargers, and elevated engine temperatures.
• Overfilling: May cause the crankshaft to whip the oil, introducing air bubbles, reducing effective lubrication, and potentially damaging seals and catalytic converters if oil is forced into the intake or exhaust system.
• Sensor alerts: The car’s electronic monitoring can detect low or high oil levels and may issue warnings or restrict power in severe cases.
• Long-term impact: Repeated misfills can accelerate wear, shorten turbocharger life, and increase the risk of costly engine repairs.

With a sophisticated powertrain like the S6’s, following proper fill levels and heeding dashboard warnings goes a long way toward preserving performance and avoiding mechanical problems.

How to Check and Adjust the Oil Level

Depending on market, the 2018 S6 may be equipped with an electronic oil level monitoring system rather than a traditional dipstick. Regardless of the system, checking oil after a change is the only sure way to confirm that the roughly 7.9 quarts (7.5 liters) filled the engine correctly without overfilling.

Best Practices During an Oil Change

The following steps summarize best practices for an oil change on a 2018 Audi S6, focusing on ensuring the correct final oil level.

1. Drain the oil fully with the engine warm, allowing additional time for the large sump and turbo feed lines to empty.
2. Replace the oil filter with a new, compatible filter designed for the 4.0 TFSI V8.
3. Add slightly less than the full rated capacity at first (for example, about 7.0–7.3 quarts / 6.6–6.9 liters).
4. Run the engine briefly, then shut it off and allow oil to settle for several minutes.
5. Check the oil level via the MMI/electronic gauge (or dipstick if equipped).
6. Top off gradually until the level registers near the upper mark, without exceeding it.

By approaching the fill process in stages and verifying with the onboard measurement, owners and technicians can avoid overfilling while still ensuring the engine receives the amount of oil it needs.

Choosing the Right Oil for a 2018 Audi S6

Beyond volume, the type and quality of oil are central to maintaining a 2018 S6. Audi’s 4.0 TFSI engines are calibrated for high-quality synthetic oils that meet specific Volkswagen Group standards. These standards account for turbocharger operation, extended service intervals, and emissions system compatibility.

Key Factors When Selecting Oil

The following factors should guide the choice of oil for a 2018 Audi S6, in addition to reaching the correct 7.9-quart (7.5-liter) capacity.

• Manufacturer spec: Look for oil explicitly meeting the approved VW/Audi specifications (often VW 502 00 in North America, or regionally approved standard).
• Viscosity: Common choices include 5W-40 or 0W-40 fully synthetic oils, depending on climate and Audi’s local recommendations.
• Brand quality: Established premium brands that list VW approvals help ensure suitable detergency, stability, and protection at high temperatures.
• Driving profile: Frequent spirited driving or track use may justify more frequent oil changes than the maximum interval recommended by Audi.

Selecting oil that meets manufacturer specifications and fits the car’s usage pattern is as important as filling to the correct capacity, especially for a performance sedan like the S6.

Where to Confirm the Exact Capacity

While the widely accepted working figure for a 2018 Audi S6 oil change is about 7.9 quarts (7.5 liters), always treat this as a technical guideline rather than an absolute. Variations in engine code, regional manuals, and software updates to the oil monitoring system mean the official reference should come from Audi’s own documents.

Reliable Sources of Information

The following sources are the most reliable ways to verify the oil capacity and specifications for a specific 2018 S6 vehicle.

• Owner’s manual: The primary reference for oil capacity, type, and service intervals for your exact model and engine.
• Service booklet or digital maintenance schedule: May contain updated oil standards or interval recommendations.
• Audi dealer or authorized service center: Can access your vehicle record by VIN and confirm the correct data for your specific configuration.
• Technical Service Bulletins (TSBs): In rare cases, Audi may update recommendations; dealers can check for relevant bulletins.

Using these sources to confirm the approximate 7.9-quart (7.5-liter) figure ensures both accuracy and compliance with Audi’s latest guidance for your S6.

Summary

The 2018 Audi S6, equipped with its 4.0-liter twin-turbo V8, generally requires about 7.9 US quarts (7.5 liters) of fully synthetic engine oil when changing oil and filter. That capacity must be paired with oil that meets the correct VW/Audi specifications and appropriate viscosity, such as 5W-40 or 0W-40, depending on climate and regional guidance. Because even small deviations in oil level can affect the health of this high-performance engine, the best practice is to fill slightly under the listed capacity, verify via the car’s oil-level system, and top off cautiously—always cross-checking with the owner’s manual or an Audi dealer for the most precise figure for your individual vehicle.