DecodedCars2018 Audi S4
Trims, performance, features, fuel economy, safety and known problems — with the pros and cons against similar 2018 models.
- Class
- Compact Cars
- Body styles
- 4dr Sedan
- Engines
- 3.0L 6-cyl turbo
- Drivetrain
- All-Wheel Drive
- Fuel
- Premium Gasoline
- MPG (best)
- 24 combined · 21 city / 30 hwy
- Length
- 186.2 in
- Curb weight
- 3,792 lb
- NHTSA rating
- Not rated
- Recalls
- 2 campaigns
Pros & cons
What's good
Nothing stands out against similar models in the data.
Watch out for
- Premium fuel requiredEvery gasoline version is rated for premium, which raises running costs.
Calculated from EPA, NHTSA and vPIC data against 39 similar 2018 models — not a review. How we calculate this →
Overview
The 2018 Audi S4 is a compact car offered with a 3.0L 6-cyl turbo engine and all-wheel drive.
It measures about 186 inches long and 71 inches wide on a 111-inch wheelbase, with a curb weight of roughly 3,792 lb.
EPA rates its most efficient version at 24 MPG combined (21 city / 30 highway), 11% worse than the 2018 compact car average of 27 MPG, for an estimated $3,400 a year in fuel.
NHTSA has not published a 5-Star overall rating for this model year.
It has 2 recall campaigns on file and owners have filed 7 complaints with NHTSA since 2015, most often about the engine.
What changed for 2018
- Engine added: 3.0L 6-cyl turbo
- Engine dropped: 3.0L 6-cyl
- Best combined MPG up from 21 to 24
Compared with 2016; trim, feature and price changes aren't covered. See the 2016 S4 →
Dimensions & weight
| Body | Length | Width | Height | Wheelbase | Track F / R | Curb weight | Weight F/R |
|---|---|---|---|---|---|---|---|
| 4dr Sedan | 186.2 in | 71.3 in | 55.1 in | 111 in | 61.8 / 61 in | 3,792 lb | 56/44 |
Transport Canada CVS (Open Government Licence – Canada), Canadian-market figures.
Will it fit your garage? Check with your measurements →Engines, MPG & running costs
| Version | Engine | Transmission | Drive | City / Hwy / Comb | vs. class | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|---|---|
| S4 | 3.0L 6-cyl turbo | Automatic (AM-S8) | All-Wheel Drive | 21 / 30 / 24 | -11% | $3,400 | 374 |
EPA estimates; "vs. class" is combined MPG against the 2018 EPA class average. How we calculate this →
Safety ratings & technology
| Version | Overall | Frontal | Driver / passenger | Side | Side pole | Rollover | Rollover risk |
|---|---|---|---|---|---|---|---|
| 2018 Audi S4 4 DR AWD | Not rated | Not rated | –★ / –★ | Not rated | Not rated | ★★★★★ | 9.9% |
Similar 2018 compact cars
| Model | Best MPG / range | NHTSA overall | Recalls |
|---|---|---|---|
| 2018 Audi S4 (this car) | 24 MPG | Not rated | 2 |
| 2018 BMW 3 Series | 36 MPG | ★★★★★ | 0 |
| 2018 BMW 5 Series | 30 MPG | Not rated | 0 |
| 2018 Mercedes-Benz E-Class | 25 MPG | ★★★★★ | 0 |
| 2018 Lexus IS | 26 MPG | Not rated | 1 |
| 2018 Audi A4 | 31 MPG | Not rated | 4 |
| 2018 Mercedes-Benz C-Class | 30 MPG | Not rated | 0 |
Recalls (2)
Air Bags › Sensor › Occupant Classification › Front Passenger · Nov 10, 2021
NHTSA campaign 21V874000 · 208,332 vehicles
- Problem
- 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.
- Fix
- 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.
Air Bags › Frontal › Passenger Side › Inflator Module · Jul 24, 2019
NHTSA campaign 19V547000 · 145,337 vehicles
- Problem
- 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.
- Fix
- 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.
Not every 2018 Audi S4 is affected — only a VIN check confirms your car.
Owner-reported problems
Unverified owner reports; best-sellers collect more.
Used 2018 Audi S4 buyer's checklist
- Run the VIN at nhtsa.gov/recalls. 2 recalls this year — ask for proof of repairs.
- Engine — 4 owner reports. Cold-start the engine, listen for knocking, and watch for warning lights or hesitation on acceleration.
- Power Train — 1 owner reports. Test-drive through all gears, including reverse; note slipping, harsh or delayed shifts.
- Vehicle Speed Control — 1 owner reports. Ask the seller and mechanic specifically about this system.
- Mileage to watch. Owners typically reported problems around 4,000 miles; ask what was repaired near that point.
- Before you pay: service records, a history report and an independent inspection.
Generated by DecodedCars from NHTSA recalls and owner complaints for the 2018 Audi S4. Not a substitute for a professional inspection.
Other S4 years
Compare all years →| Year | MPG (best) | Length | Overall | Recalls | Complaints |
|---|---|---|---|---|---|
| 2025 S4 | 24 | 187.8 in | Not rated | 0 | 0 |
| 2024 S4 | 24 | 187.8 in | Not rated | 0 | 0 |
| 2023 S4 | 24 | 187.8 in | Not rated | 0 | 0 |
| 2022 S4 | 24 | 187.8 in | Not rated | 1 | 1 |
| 2021 S4 | 23 | 187.8 in | Not rated | 4 | 2 |
| 2020 S4 | 23 | 187.8 in | Not rated | 3 | 17 |
| 2019 S4 | 24 | 186.2 in | Not rated | 1 | 2 |
| 2016 S4 | 21 | 185 in | Not rated | 0 | 0 |
| 2015 S4 | 21 | 185 in | Not rated | 1 | 1 |
| 2014 S4 | 21 | 185 in | Not rated | 1 | 17 |
| 2013 S4 | 21 | 185 in | Not rated | 1 | 15 |
| 2012 S4 | 21 | 185 in | Not rated | 1 | 21 |
Sources: EPA, NHTSA, Transport Canada, Wikimedia Commons. Not affiliated with NHTSA, the EPA or Audi. How we calculate this →