2021 Audi S4
Recalls, most-reported problems, crash-test ratings, fuel economy and what a 2021 Audi S4 is worth — from official NHTSA and EPA data. 10 on record.
2021 Audi S4 at a glance
Included: that car's specs and build sheet, model-year recall campaigns and a fair price.
2021 Audi S4 recalls 4
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Audi A8, RS7, RS6 Avant, RS5 Sportback, RS5 Coupe, Q8, Q7, Q5 Sportback, S4 Sedan, Q5, A7, A6, A6 Allroad, A5 Sportback, A5 Coupe, A5 Cabrioleet, A4 Sedan, A4 Allroad, E-Tron Sportback Quattro, SQ7, S5 Cabriolet, E-Tron Quattro, SQ8, SQ5 Sportback, SQ5, S8, S7, S6 Sedan, S5 Sportback, S5 Coupe, 2022 E-Tron GT, and 2021-2022 RSQ8 vehicles. Due t…
Fix: Dealers will update the infotainment unit software, free of charge. Owner notification letters were mailed October 25, 2022. Owners may contact Audi's customer service at 1-800-253-2834. Volkswagen's number for this recall is 91DZ.
Volkswagen Group of America, Inc. (Audi) is recalling certain 2019-2021 Audi A5 Sportback, RS5 Coupe, RS5 Sportback, S5 Sportback, 2020-2021 A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A6 Allroad, A6 Sedan, A7, A8, Q5, S4 Sedan, S5 Coupe, S5 Cabriolet, S6 Sedan, S7, S8, SQ5, 2021 Q5 Sportback, Q7, Q8, RS6 Avant, RS7, RSQ8, SQ5 Sportback, SQ7, and SQ8 vehicles. The rear axle alignment may not have been inspected af…
Fix: Dealers will inspect the rear axle, adjust the alignment as necessary, and replace any prematurely or unevenly worn tires, free of charge. Owner notification letters were mailed March 3, 2022. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 42L5.
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2021 Volkswagen ID4, Audi A4 Allroad, A4 Sedan, A5 Cabriolet, A5 Coupe, A5 Sportback, A6 Allroad, A6 Sedan, A7, A8, E-Tron Quattro, E-Tron Sportback Quattro, Q3, Q5, Q5 Sportback, Q7, Q8, RS5 Sportback, RS5 Coupe, RS6 Avant, RS7, RSQ8, S4 Sedan, S5 Cabriolet, S5 Coupe, S5 Sportback, S6 Sedan, S7, S8, SQ5, SQ5 Sportback, SQ7, SQ8, and 2021-2022 S3 Se…
Fix: Dealers will inspect, and replace as necessary, the middle-rear seat belt assemblies, free of charge. Owner notification letters were mailed August 27, 2021. Owners may contact Volkswagen customer service at 1-800-893-5298 and Audi customer service at 1-800-253-2834. Volkswagen's numbers for this r…
Volkswagen Group of America, Inc. (Audi) is recalling certain 2021 Q7, Q8, Q5 Sportback, SQ5 Sportback, RS6 Avant, RS7, RS Q8, 2020-2021 Audi S6 sedan, Q5, A8, S8, A7, A6 Allroad, A5 Cabriolet, A4 sedan, A4 Allroad, SQ5, S7, A6 sedan, S5 coupe, S4 sedan, S5 Cabriolet, A5 coupe, 2019-2021 RS5 coupe, A5 Sportback, S5 Sportback, RS5 Sportback vehicles. The lock nut on the trailing arm of the rear axle may break due to …
Fix: Dealers will replace the lock nuts and, if necessary, the associated bolts, free of charge. Owner notification letters were mailed June 4, 2021. Owners may contact Audi customer service at 1-800-253-2834. Audi's number for this recall is 42L1.
Source: U.S. NHTSA, checked 4 Nov 2026. A campaign covers the model year; to see whether a particular car still needs the repair, check its VIN on NHTSA.gov or ask a franchised dealer.
2021 Audi S4 common problems
The most-reported problem areas across all 2 owner complaints filed with NHTSA — and what to check before you buy.
2021 Audi S4 safety ratings
Rollover risk: 9.9% — NHTSA's estimated chance of rollover in a single-vehicle crash (dynamic test: no tip).
Source: NHTSA 5-Star Safety Ratings (NCAP), tested as the 2021 Audi S4 4 DR AWD. Ratings can differ by body style and drivetrain.
2021 Audi S4 MPG & running costs
Source: U.S. EPA / DOE fueleconomy.gov.
Estimated 5-year cost to own
A rough guide to what running a 2021 Audi S4 costs over five years and 75,000 miles.
How this is estimated: fuel is the U.S. EPA annual cost at 15,000 miles a year. There aren't enough comparable listings to estimate depreciation for this model, so it is left out. Not included: insurance, maintenance, repairs, taxes, registration and finance costs. Treat it as a comparison guide, not a quote.
Dimensions & weight
Manufacturer-reported figures for the 2021 Audi S4. Source: Transport Canada vehicle specifications via NHTSA.
Investigations & service bulletins
Manufacturer service bulletins 969
Technical notes the manufacturer sent to dealers about known issues and fixes. Useful to mention to a mechanic — they are not recalls and repairs may not be covered. Showing the 10 most recent of 969.
This bulletin provides information for reporting safety related information to the manufacturer.
Bulletin TSB_2052680_2 · Sep 2026This bulletin states that technicians are required to report to the manufacturer when a vehicle has flooded, and specify the height to which the vehicle has been flooded.
Bulletin TSB_2083409_1 · Sep 2026This bulletin provides service information regarding exterior glass cleaning.
Bulletin TSB_2020552_15 · Visibility/wiper · Sep 2026This bulletin provides informaiton when DTC B200FF0 is stored.
Bulletin TSB_2065871_4 · Steering · Sep 2026This bulletin provides information about vibrations and rotational steering vibrations.
Bulletin TSB_2074846_5 · Steering · Sep 2026This bulletin provides information when the rear parking sensor sometimes does not work, rear parking sensor loose, rear parking sensor fault message.
Bulletin TSB_2068573_6 · Electrical System · Sep 2026This bulletin provides information about billing for a broken sunroof glass panel.
Bulletin TSB_2078648_4 · Structure · Sep 2026This bulletin provides information when the license plate mounting bracket threded inserts are stripped.
Bulletin TSB_2030471_9 · Sep 2026This bulletin provides information when there are stails/marks on the sill panel trim.
Bulletin TSB_2073860_2 · Structure · Sep 2026This bulletin provides information when there is an abnormal knocking noise from the engine compartment; V6 3.0L TFSI.
Bulletin TSB_2081030_4 · Engine · Sep 2026Source: NHTSA Office of Defects Investigation, listed for the S4 AWD. Model-year data, not specific to one car.
Canadian recalls 4
Transport Canada recall campaigns for the 2021 Audi S4. Relevant if the car was first sold in, or imported from, Canada.
Visual System
Issue: On certain vehicles, a software problem could cause the rearview camera image not to appear on the display. Canadian regulations require the rearview image to display when the transmission is shifted into reverse gear. Safety Risk: A rearview camera image that does not display could reduce a driver's ability to see behind the vehicle while backing up. This could increase…
Transport Canada #2022565 · Oct 2022Suspension
Issue: On certain vehicles, the rear wheel alignment was not checked during recall 42L1 (Transport Canada Recall 2021-249). As a result, the steering could pull to one side or another and the tires could wear unevenly. If you continue to drive the vehicle in this condition, there may be reduced traction. Eventually, a tire could fail and lose air pressure. Safety Risk: A tire f…
Transport Canada #2022022 · Jan 2022Seats And Restraints
Issue: On certain vehicles, the passenger seat belt assemblies may contain defective automatic locking retractors (ALR). As a result, the seat belts may not properly lock to secure a child seat. Safety Risk: A seat belt that is used to secure a child restraint but is not properly locked could increase the risk of injury in a crash. Corrective Actions: Audi will notify owners by…
Transport Canada #2021486 · Aug 2021Suspension
Issue: On certain vehicles, the lock nuts for the rear trailing arm bolts may be defective. If a nut breaks, there could be sudden changes in rear wheel alignment. This can cause a loss of vehicle stability. Safety Risk: Reduced vehicle stability could cause a loss of control and increase the risk of a crash. Corrective Actions: Audi will notify owners by mail and instruct you…
Transport Canada #2021249 · Apr 2021Source: Transport Canada Motor Vehicle Safety Recalls Database.
About the Audi S4
The Audi S4 is the high performance variant of Audi's compact executive car A4. The original Audi S4, built from 1991 until 1994, was a performance-oriented version of Audi's 100 saloon/sedan. All subsequent S4s, beginning with the "B5" platform car in 1997, have been based on the Audi A4; and as the A4 has evolved from one generation to the next, so has the S4. Audi's platform generation names, beginning with "B5" in 1997, are used throughout to distinguish between generations/evolutions of these products.
From Wikipedia, licensed CC BY-SA 4.0. Describes the model line in general, not this model year specifically.