YearToAvoid

2018 Audi S4 Problems, Recalls & Reliability

Verdict

Good

Complaint Index

40/100

#7 most-complained of 11 S4 years

The 2018 Audi S4 has a Complaint Index of 40, ranking 7th out of 11 model years, with a "Good" verdict relative to other S4 years. NHTSA lists 7 complaints and 2 recalls, with Engine issues making up 57% of complaints.

Complaints
7
Recalls
2
Crashes / fires
0 / 0
Injuries / deaths
0 / 0
NHTSA overall rating
Not rated
EPA combined MPG
24
21 city / 30 hwy

Top 2018 Audi S4 problems

NHTSA owner complaints by component group. Groups with 15+ complaints have their own page.

  1. Engine4 (57%)
  2. Brakes1 (14%)
  3. Structure & Body1 (14%)
  4. Suspension, Wheels & Tires1 (14%)
  5. Transmission & Powertrain1 (14%)

What owners report

  • Owners report a 1-2 second delay when transitioning from throttle to off-throttle in manual mode, causing the vehicle to keep accelerating briefly, especially in first gear.
  • Owners describe underride guard panels on the vehicle's underside breaking free from loose plastic clips after collecting rain or snow, then contacting the road.
  • Owners report the pre-sense auto-braking system triggering erroneous, aggressive braking jolts on curves and hills, with no way to disable the feature.
  • Owners describe rear springs breaking and mounts deteriorating, which a dealer inspection linked to a defect pattern in this model year.
  • Owners report PCV housing and line failures that build pressure and force oil out of the oil cap, located near the turbo.
  • Owners describe knocking noises from loose rocker arm needle bearings that shed metal shavings into the oil and destroy the engine from the inside.
2018 Audi S4 complaints: complaints filed per month2Nov 2017Feb 2018Apr 2018Dec 2022Apr 2024Mar 2025Jun 2025
8 complaints filed with NHTSA from Nov 2017 to Jun 2025; peak Nov 2017 (2).

2018 Audi S4 recalls

2 NHTSA recall campaigns list this model year.

  1. NHTSA 21V874000Nov 10, 2021Airbags208,332 vehicles

    Air bags:sensor:occupant classification:front passenger

    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.

    Risk: A disabled passenger air bag increases the risk of injury in the event of a crash.

    Remedy: Dealers will replace the connecting cable and either the heating mat or entire seat cover, free of charge. Owner notification letters were mailed January 7, 2022. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 74E3. This recall is an expansion of Recall 19V-547 (74D9). Vehicles previously repaired under 19V-547 will need to return for the new remedy.

  2. NHTSA 19V547000Jul 24, 2019Airbags145,337 vehicles

    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.

    Risk: A disabled passenger air bag increases the risk of injury in the event of a crash.

    Remedy: Audi will notify owners, and dealers will install cable ties to the harness, free of charge. The recall began September 9, 2019. Owners may contact Volkswagen customer service at 1-800-893-5298. Audi's number for this recall is 74D9.

2018 Audi S4 fuel economy and fuel cost

City
21 MPG
Highway
30 MPG
Combined
24 MPG
Annual fuel cost (EPA)
$3,300
15,000 mi/yr
Fuel
Premium
Current regular gas
$4.32/gal
national avg.

EPA figures; median across configurations of this model year. Estimate your own cost with the fuel cost calculator.

2018 compared with other S4 years

Complaint Index by model year (0 = fewest issues, 100 = most)025507510020102011201220132014201520182019202020212022
Complaint Index: 0 = fewest issues, 100 = most, relative to other years of this model. Avoid Caution Good Best
YearVerdictIndexComplaintsRecallsMPG
2014Caution5017120.5
2015No verdict01120.5
2018Good407224
2019No verdict202124
2020Caution6016323

All Audi S4 years: best and worst →

Frequently asked questions

Is the 2018 Audi S4 reliable?
Compared to other S4 model years, the 2018 has a Complaint Index of 40 and ranks 7th out of 11 years tracked, earning a "Good" verdict based on NHTSA complaints and recalls.
What is the most common problem with the 2018 Audi S4?
Engine problems are the top issue, accounting for 57% of complaints (4 of 7), with a median failure mileage of 1,300 miles among those cases.
Does the 2018 Audi S4 have any recalls?
NHTSA lists 2 recalls for the 2018 Audi S4, both related to airbags, neither marked as do-not-drive.
How does the 2018 Audi S4 compare to other S4 years?
The 2018 model's Complaint Index of 40 is lower than the worst years like 2010 (100) and 2013 (90), placing it among the better S4 model years based on NHTSA data.

Sources: NHTSA Office of Defects Investigation complaint and recall databases; U.S. EPA fuel economy data; NHTSA 5-Star Safety Ratings. Complaints are unverified owner reports.

Data updated Sep 24, 2026. Read the methodology and data sources. The Complaint Index is based on NHTSA owner complaints and recalls; it is not a reliability rating.