2018 Audi S4 Reliability ReportB grade · moderate risk · system-by-system breakdown
Quick Facts · 2018 Audi S4
- The system most likely to surface first: electrical/infotainment system (moderate severity).
- Has 2 NHTSA recalls on record — the most notable involves the air bags:frontal:passenger side:inflator module.
- Outscores the 2016 Audi S4 by 15 points — one of the stronger nearby years to consider.
Is the 2018 Audi S4 Worth Buying?
The 2018 Audi S4 is a potent, sophisticated sport sedan that offers remarkable daily drivability with exhilarating performance. While its core mechanicals are generally solid, particularly the engine and transmission, buyers must anticipate higher-than-average luxury maintenance costs and be prepared for potential complex electrical system diagnostics as the vehicle ages.
The 2018 Audi S4 is an exceptional performance sedan that delivers an exhilarating driving experience and premium comfort. While its core engine and transmission are generally reliable, the complex electronics and specific engine component wear points elevate the risk of costly repairs. Buy one only if you have a cl…
Best Model Years
2018-2020 (initial B9 generation models are generally consistent)
Years to Avoid
None within the B9 S4 generation, as the 2018 model represents a solid iteration.
Biggest Strengths
- Robust ZF 8-speed automatic transmission
- Excellent build quality and premium interior materials
- Powerful and generally reliable EA839 3.0L TFSI engine
What Tends to Fail First on the 2018 Audi S4
The systems that tend to fail first on the 2018 Audi S4, with the typical mileage window when each becomes a concern. Detailed repair-cost ranges and exact what-to-check inspection notes are in the full report.
Owners report intermittent MMI freezes, reboots, and occasional glitches with the Virtual Cockpit or advanced driver-assist sensors. Diagnosis can be time-consuming and expensive at dealerships.
The PCV (Positive Crankcase Ventilation) valve, often integrated into the valve cover, can fail, leading to oil consumption, rough idle, or a check engine light. Failure can also create vacuum leaks.
Plastic components within the cooling system, specifically the thermostat housing and water pump, are prone to leaks or premature failure, which can lead to overheating if not addressed promptly.
2018 Audi S4 Mileage Danger Zones
The mileage windows when the 2018 Audi S4 most commonly needs attention. Plan ahead, budget accordingly, and inspect before you cross each threshold.
Low Risk Zone
At this mileage, the vehicle is still relatively new. Most issues would be covered under the factory warranty (if still active for initial years). Keep an eye out for early electrical glitches or unusual noises, which could indicate a mi…
Maintenance Zone
This is a critical service interval. Expect significant routine maintenance, including spark plugs, possibly differential fluids, and a recommended transmission fluid change (despite Audi's 'lifetime' claim). Monitor for PCV valve sympto…
Elevated Risk Zone
Components that last well into higher mileage will start to show wear. Expect to address suspension bushings, potential leaks from engine seals, and increased monitoring of the turbocharger for any unusual noises or performance degradation.
High Risk Zone
At this point, you're venturing into territory where major components like the turbocharger, engine mounts, or advanced suspension elements may require significant repair or replacement. Comprehensive maintenance history is paramount, as…
2018 Audi S4 Ownership Cost Outlook
What it typically costs to keep the 2018 Audi S4 on the road. Full 5-year cost-of-ownership projection and major-failure-risk forecast are in the report.
Annual Maintenance
$800-1,200
Moderate Repairs
$1,000-2,500 occasionally (e.g., PCV, cooling system, suspension bushings)
How Long Does the 2018 Audi S4 Last?
For a 2018 S4, prioritize examples with under 60,000 miles to minimize immediate major repair risks. If considering higher mileage, a comprehensive pre-purchase inspection and a robust maintenance history are absolutely non-negotiable.
What 2018 Audi S4 Owners Actually Say
What Owners Love
- Blistering acceleration and confident quattro all-wheel drive grip in all conditions.
- Luxurious, high-quality interior with excellent ergonomics and technology (when working).
- Understated styling that blends performance with everyday elegance.
- Remarkable daily drivability, equally comfortable on commutes and spirited drives.
Common Frustrations
- High cost of routine maintenance and repair parts, even for minor issues.
- Frustrating intermittent electrical glitches with the MMI or Virtual Cockpit.
- Firmer ride quality can be jarring on poorly maintained roads, especially with larger wheels.
- Higher fuel consumption than advertised if driven enthusiastically.
Who Should Buy the 2018 Audi S4?
Best For
- Performance enthusiasts seeking a practical daily driver with AWD.
- Luxury buyers who appreciate German engineering and interior quality.
- Individuals who prioritize driving dynamics and premium features.
Not Ideal For
- Budget-conscious buyers seeking minimal ownership costs.
- Anyone who habitually neglects scheduled maintenance.
How the 2018 Audi S4 Compares to Rivals
The 2018 S4 generally holds its own in the performance luxury segment, offering a compelling blend of power, AWD grip, and interior refinement. It typically boasts better long-term reliability than some more exotic competitors, but doesn't quite reach the bulletproof status of…
More Reliable Than
- Alfa Romeo Giulia Quadrifoglio (often plagued by more frequent and severe electrical issues)
- Mercedes-AMG C43 (often has more prevalent mild hybrid system issues and sometimes less robust build quality in specific model years)
- BMW M340i (some G20 340i models had early software glitches, though B58 engine is strong)
Comparable To
- BMW M340i (G20 generation with B58 engine - both offer robust powertrains with complex electronics)
- Mercedes-Benz C43 AMG (W205 generation - similar blend of performance and luxury, with comparable maintenance expectations)
2018 Audi S4 Recall History
2 recalls on record from NHTSA. Check your VIN atnhtsa.gov to see if the repair was performed.
AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE
Volkswagen Group of America, Inc. (Audi) is recalling certain 2018-2019 Audi RS5 Sportback, 2018 S5 Cabriolet, S5 Sportback, S5 Coupe, S4 Sedan, A5 Cabriolet, A5 Sportback, A5 Coupe, and 2017-2018 A4 Sedan and A4 Allroad vehicles. Oxidation on the Passenger Occupant Detection System (PODS) connecting cable may cause the software to misdiagnose a malfunction and disable the passenger air bag.
SEATS
Volkswagen Group of America, Inc. (Audi) is recalling certain 2017-2020 A4 Allroad, A4 Sedan, 2018-2019 RS5 Coupe, 2019 RS5 Sportback, 2018-2020 A5 Cabriolet, A5 Coupe, A5 Sportback, S4 Sedan, S5 Cabriolet, S5 Coupe, and Audi S5 Sportback vehicles. The cable connecting the seat heater to the Passenger Occupant Detection System (PODS) may have a contact fault, causing the software to misdiagnose a malfunction and disable the passenger air bag.
What breaks on the 2018 Audi S4?
Full reliability breakdown — engine, transmission, rust, electrical. With repair costs and mileage danger zones.
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Other Audi S4 Years to Consider
Compare KeepScores across nearby years of the Audi S4. Click any year for its full report.
2018 Audi S4 Alternatives
Similar class, similar year range — ranked by KeepScore.
Relevant Products for Your 2018 Audi S4
Parts and accessories matched to your 2018 Audi S4
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Frequently Asked Questions
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