What are the most common problems with the 2018 Audi S8?

The 2018 Audi S8's reliability is rated below average, primarily due to a high TSB count and a recall concerning the engine compartment seal.

How many recalls does the 2018 Audi S8 have?

The 2018 Audi S8 currently has 1 recall on file. Review the full recall report to see affected components and available remedies.

Is the 2018 Audi S8 a good buy used?

Verdict: Proceed with caution. The 2018 Audi S8's reliability is rated below average, primarily due to a high TSB count and a recall concerning the engine compartment seal. A single recall for the engine compartment seal requires verification of the remedy's proper installation. Despite no reported owner complaints, the extensive TSB list indicates potential underlying issues across various systems. Expect high fuel costs with a combined EPA rating of 18 MPG. The vehicle's complexity means potential for costly repairs, especially if TSB-related issues are not addressed proactively. Always verify service history, open recalls, and maintenance records before purchasing.

What maintenance costs should I expect for the 2018 Audi S8?

Refer to the maintenance cost guide for interval schedules, DIY difficulty ratings, and typical repair cost ranges for the 2018 Audi S8.

2018 Audi S8 Report

Known issues, recalls, running costs, and what to check before you buy.

Updated Jun 2, 2026Ryan Davis

Overall Score

Our Verdict

Proceed with caution

Key Takeaways

The 2018 Audi S8's reliability is rated below average, primarily due to a high TSB count and a recall concerning the engine compartment seal.
A single recall for the engine compartment seal requires verification of the remedy's proper installation.
Despite no reported owner complaints, the extensive TSB list indicates potential underlying issues across various systems.
Expect high fuel costs with a combined EPA rating of 18 MPG.

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Overview

2018 Audi S8

The 2018 Audi S8 is a formidable luxury sedan that blends potent V8 power with sophisticated all-wheel-drive dynamics. Beneath its understated exterior lies a twin-turbocharged 4.0-liter engine producing a substantial 605 horsepower in the 'Plus' trim, paired with an eight-speed automatic transmission. While offering exhilarating acceleration and a refined ride, its complexity and below-average reliability verdict warrant a cautious approach for used car buyers. The high number of Technical Service Bulletins (TSBs) suggests potential for various issues, even if owner complaints are minimal.

Critical Failure Risk

The 4.0L twin-turbo V8 engine can develop oil leaks, often from valve cover gaskets or oil cooler seals. These leaks can lead to low oil levels and potential engine damage if not addressed promptly.

Early detection can help you avoid a $2,000-$4,000 repair.

Open Maintenance Analysis →

Safety & Bulletins

Open Recalls1

Service Bulletins0

Full Recall History →

Owner Complaints

No primary complaint themes found.

Detailed Issue Breakdown →

Performance & Efficiency

Horsepower: 605HP
Torque: 517 lb–ftLB-FT

Fuel Efficiency

Combined

MPG

City

MPG

Highway

MPG

Full Vehicle Specifications ↓

Reliability

Practicality

The score is mainly limited by high fuel consumption.

Buyer Fit

Who This Car Is For

Best for

Enthusiasts seeking potent V8 performance and all-wheel-drive capability in a luxury sedan package.

+2 more buyer-fit notes in the full report

Avoid if

Drivers who prioritize bulletproof reliability and low running costs.

+2 more buyer-fit warnings in the full report

2018 Audi S8 Reliability Analysis

Specs

Vehicle Specs

Fuel Type: Premium
Seating Capacity: 5
Horsepower: 605 hp
Torque: 517 lb-ft
Transmission: Automatic (S8)
Drivetrain: All-Wheel Drive
Body Style: Sedan
MSRP Range: $115,900 - $115,900
EPA Combined MPG: 18

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Unlock the complete checklist, maintenance outlook, and buyer verdict in one place.

Most Common Issues

1. Engine Oil Leaks

Most reported

Usage data observed

2. Turbocharger Issues

Usage data observed

See all common issues in the maintenance guide

First Service Interval

- Oil Change (5W-40 Synthetic) (Parts: 5W-40 Synthetic Engine Oil, Oil Filter) - Tire Rotation and Inspection - Brake System Inspection - Fluid Level Check (Coolant, Brake, Power Steering)

Est. shop cost: $150 - $250

10,000 mi

Unlock the full maintenance guide for every scheduled service interval and cost forecast.

Full pre-purchase inspection checklist

Complete maintenance schedule (5 service intervals)

Repair forecasts with mileage and cost context

Full buyer-fit guidance and who should avoid it

Full specs and trim-level context

1 recall campaign details & remedy notes

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FAQ

Is the 2018 Audi S8 reliable?

The CarFocal Reliability Score for the 2018 Audi S8 is 8.8/10. Reliability score is 8.8/10. NHTSA recalls: 1. Owner complaints: 0.

How practical is the 2018 Audi S8 for daily use?

Practicality score is 4.6/10. The score is mainly limited by high fuel consumption. EPA combined economy is 18 MPG. Seating capacity is 5. 4 passenger doors are listed. Boot capacity is 402 litres.

What is the overall score for the 2018 Audi S8?

The CarFocal Overall Score for the 2018 Audi S8 is 6.4/10. Overall score is 6.4/10 (Mixed). Confidence 55%. Maintenance 8.5/10. Practicality 4.6/10.

What does it cost to own and maintain a 2018 Audi S8?

Based on Carfocal's data, First listed service: - Oil Change (5W-40 Synthetic) (Parts: 5W-40 Synthetic Engine Oil, Oil Filter) - Tire Rotation and Inspection - Brake System Inspection - Fluid Level Check (Coolant, Brake, Power Steering) at 10,000 miles. Estimated first-year maintenance: $700 - $1,200. Repair prediction highlight: Engine Oil Seals (Valve Cover, Oil Cooler) (typical at 75,000 miles, estimated cost Min: $500 • Max: $1500).

What is the MSRP range for the 2018 Audi S8?

MSRP range is $115,900 - $115,900.

What engine is in the 2018 Audi S8?

Engine specs list 4.0T • 8 • 4.0. Output is 605 hp • 517 lb-ft.

What transmission does the 2018 Audi S8 use?

According to CarFocal's specs for the 2018 Audi S8, transmission is Automatic (S8). The paired drivetrain is All-Wheel Drive.

Does the 2018 S8 require Premium gas?

Manufacturer fuel recommendation: Premium.

What is the combined EPA MPG for the 2018 Audi S8?

EPA combined estimate is 18 MPG.

What driver assistance and safety features are available on the 2018 Audi S8?

13 standard driver assistance features. Key features include Anti-lock Braking System, Electronic Stability Control, Traction Control.

What is the fuel economy range for the 2018 Audi S8?

According to CarFocal's specs for the 2018 Audi S8, fuel economy range is 14-24 mpg combined.

How many people fit in a 2018 Audi S8?

According to CarFocal's specs for the 2018 Audi S8, seating capacity is 5.

What body style is the 2018 Audi S8?

According to CarFocal's specs for the 2018 Audi S8, body style is sedan.

What drivetrain does the 2018 Audi S8 use?

According to CarFocal's specs for the 2018 Audi S8, drivetrain is All-Wheel Drive. Transmission is Automatic (S8).

Are there open safety recalls on the 2018 Audi S8?

This model year has 1 official safety campaigns listed.