Problems owners report
Complaints filed with NHTSA about the 2021 Audi S4, by the system named in each complaint. One complaint can name several.
- Electrical system1
- Unknown or other1
NHTSA ODI complaints (public domain) · updated 23 Oct 2026 · 0 injuries and 0 deaths reported
Compared with other years
NHTSA ODI complaints by model year
New York safety inspections
At its first New York inspection the 2021 Audi S4 failed the safety check 0.49% of the time — 48% less often than the average 2021 passenger car (0.95%). Median odometer at inspection: 22,699 miles.
NY DMV Vehicle Inspections (vezn-fmmk), initial inspections since Aug 2021 · how we count
Registered new in Europe in 2021
445 new Audi S4 cars were registered in the EU, Norway and Iceland in 2021; the largest markets were Germany (324), France (36), Italy (35).
- Average mass
- 1,905 kg
- Average CO₂
- 191 g/km (WLTP)
- Average power
- 251 kW
- Fuel type recorded
- Diesel 99% · Petrol 0.7%
European Environment Agency, CO₂ emissions from new passenger cars · averages weighted by registrations; CO₂ is the type-approval value; fuel type as recorded at registration, where many non-plug-in hybrids appear as petrol · re-use permitted with acknowledgement
Real-world fuel consumption
172 Audi S4 cars first registered in Europe in 2021 report their fuel use through the on-board meter. Diesel hybrid versions use 8.2 l/100 km on the road against 7.3 in the WLTP test (+13%).
| Fuel | Cars | On the road | WLTP | Difference |
|---|---|---|---|---|
| Diesel hybrid | 172 | 8.2 | 7.3 | +13% |
Litres per 100 km from the cars' own fuel meters (OBFCM), collected in 2024; the year is the year of first registration. All years together · European Environment Agency · CC BY 4.0
In the United Kingdom
148 cars built in 2021 were licensed for the road at the end of 2025, and 1 more were declared off the road (SORN).
Department for Transport and DVLA, vehicle licensing statistics (table VEH0124, year of manufacture) · Open Government Licence v3.0
In New Zealand
17 2021 cars are on the New Zealand register; 12% arrived as used imports, 88% were sold new in New Zealand.
NZ Transport Agency Waka Kotahi, Motor Vehicle Register (March 2026) · CC BY 4.0
Crash-test ratings
NHTSA 5-star results for 1 variant; not yet fully rated. Rollover risk is the estimated chance of rolling over in a single-vehicle crash.
| Variant | Overall | Rollover risk |
|---|---|---|
| 2021 Audi S4 4 DR AWD | — | 9.9 % |
- Electronic stability control
- Standard
- Forward collision warning
- Standard
- Lane departure warning
- Standard
- Best overall rating
- —
NHTSA New Car Assessment Program (5-Star Safety Ratings), api.nhtsa.gov · US federal work, public domain
Fuel consumption
Official Canadian test results for 1 variant: combined 10.1 L/100 km (about 23 mpg US), CO₂ 237 g/km.
| Variant | City | Highway | Combined |
|---|---|---|---|
| S4 Sedan quattro · Compact · Premium gasoline | 11.5 | 8.5 | 10.1 |
Litres per 100 km. Natural Resources Canada, Fuel consumption ratings (open.canada.ca) · Open Government Licence – Canada
Recalls in Canada
4 Transport Canada recalls for the 2021 Audi S4.
| 2022565 5 Oct 2022 | 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 i… |
| 2022022 26 Jan 2022 | Suspension 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 pu… |
| 2021486 4 Aug 2021 | Seats 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 p… |
| 2021249 26 Apr 2021 | Suspension 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 align… |
Transport Canada Vehicle Recalls Database · Contains information licensed under the Open Government Licence – Canada
Recalls
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 to a software issue, a blank or black screen may be displayed instead of the rearview camera image when the vehicle is placed in reverse gear. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."
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 after the repairs for Recall 21V-295 (42L1) were performed.
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 Sedan vehicles. The rear seat belt automatic locking retractors may deactivate early, which can prevent the child restraint system from securing properly. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 208, "Occupant Crash Protection."
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 stress corrosion.
Whether a recall was fixed on a particular car is known only to the manufacturer: check the VIN at nhtsa.gov/recalls.
NHTSA recalls · summaries in NHTSA's own words
Service bulletins
What Audi told its dealers about the 2021 Audi S4: known faults, fixes and updates.
| Bulletin | Summary |
|---|---|
| 11011305 | This bulletin provides information when the camera for the Driver Assist Systems is coded incorrectly. |
| 11011303 | This bulletin provides information when the anti-theft alarm activates for no reason, or when the anti-theft alarm does not activate. |
| 11011302 | This bulletin provides information when various camera-based driver assistance systems are unavailable (DTC B200FF2 (1123875)). |
| 11011296 | This bulletin provides service-info relating to lithium-ion high-voltage batteries; determining energy content. |
| 11011285 | This TSB Provides information when parking assistance provides false warnings. |
| 11011282 | This bulletin provides information when speaker rattles, vibrations, or audio interference is noted. |
| 11011276 | This TSB provides information when DTCs U142100 and U164200 are stored as passive/sporadic in the gateway. |
| 11011274 | This bulletin provides information when the restricted function icon for Audi Pre sense is displayed after engine starts. |
| 11011270 | This bulletin provides informatoin when Audi pre sense restricted message appears in the instrument cluster, no DTCs. |
| 11011263 | This bulletin provides information regarding cleaning exterior glass. |
| 11011257 | This bulletin provides information when creaking noises are heard when body twists during braking or steering maneuvers. |
| 11011256 | This bulletin provides information when the DTCs B200FF0 to B200FF5 are stored in the J775 suspension control unit. |
| 11011240 | This bulletin provides information about professional noise analysis with the VAS 611 015 PICO-NVH tool |
| 11011239 | This bulletin advises that fuel additives are not permitted. |
| 11009983 | Vehicle Concerns Before Recall Repair Available |
| 11009967 | This bulletin provides information when there is an issue with wireless charging/wireless charging not working with Audi Phone Box. |
| 11009965 | This bulletin provides information when the calendar function is not available. |
| 11009959 | This Pending Service Solution (PSS) requests that technicians enter a record in the PSS Database when there is an Audi connect installation error. |
| 11009958 | This TSB provides information when DTCs U142100 and U164200 are stored as passive/sporadic in the gateway. |
| 11009951 | This TSB provides information when the Virtual cockpit has a pixel error. |
| 11009948 | This bulletin provides information when there is noise from the backrest of the front seat. |
| 11009941 | This bulletin provides diagnostic information regarding the locking system. |
| 11009938 | This bulletin provides information when there are droning noises/vibrations in tight corners, vehicles with PR number GH4 (quattro with ultra technology). |
| 11009936 | This bulletin provides informatin when there is binding or vibrations in tight turns with quattro Ultra. |
| 11009928 | This bulletin provides informatin when the engine does not run smoothly at idling speeds. |
NHTSA manufacturer communications (public domain)