2021 Audi S4: MPG and fuel economy
The 2021 Audi S4 is rated by the U.S. Environmental Protection Agency at 23 combined MPG, with 20 MPG in the city and 28 MPG on the highway. That lands well below the average for cars in the Compact Cars class in the same model year.
This page collects every fuel-economy figure the EPA publishes for the 2021 Audi S4. Below you will find the headline combined, city, and highway MPG, the estimated annual fuel cost at three different driving levels, the tailpipe CO₂ emissions, and a full breakdown of the engine and drivetrain. If you want to know whether this generation got more or less efficient over the years, the year-over-year table further down covers every model year the EPA has rated.
Key takeaways
- Returns 23% worse combined MPG than the average car in the Compact Cars class for the 2021 model year (30 MPG class average).
- The most efficient car in the Compact Cars class for the 2021 model year is the Kandi K27 at 114 MPG.
- The Audi S4 has gained 6 MPG since its first rated model year, the 1992 Audi S4 at 18 MPG.
- EPA estimates this car costs around $4,250 more in fuel over five years than an average new vehicle of the same model year.
- Requires premium gasoline, which typically adds about 40 to 60 cents per gallon to the EPA's annual fuel cost estimate.
Fuel economy at a glance
These are the EPA's official ratings for the 2021 Audi S4. The numbers come from a standardised laboratory test cycle and are the same figures that appear on the window sticker of every new car. Real-world mileage varies with driving style, weather, fuel quality, and how heavily loaded the car is.
Combined MPG is a 55/45 weighted blend of the city and highway test cycles. The EPA uses it as the single number you can compare across the entire dataset, including hybrids and EVs (which use the equivalent MPGe figure).
| Combined MPG | 23 MPG |
| City MPG | 20 MPG |
| Highway MPG | 28 MPG |
| Annual fuel cost | $3,000 |
| Tailpipe CO₂ | 380 g/mi |
| Fuel type | Premium |
How the 2021 Audi S4 compares
The 2021 Audi S4 returns 23 combined MPG. Cars in the Compact Cars class for the same model year average 30 MPG, which puts this car behind the class average by about 23%.
The most efficient car in the Compact Cars class for the 2021 model year is the Kandi K27 at 114 MPG. The bar chart below puts the Audi S4 alongside the class best and the class average so you can see the full picture.
For broader context, the average new car of the 2021 model year (across all classes) returns 27.9 MPG. Larger vehicles pull the all-cars average down, so do not use that figure on its own to judge a small car or a hybrid. The full list of the most efficient cars of the 2021 model year is on its own page.
Annual fuel cost across driving patterns
The headline annual fuel cost the EPA publishes assumes 15,000 miles of driving per year and a fuel mix of 55% city and 45% highway. The dollar figure is calculated using the EPA's current reference price for premium gasoline, which is $4.61/gallon. EPA updates that reference periodically rather than tracking live pump prices, so treat it as a window-sticker estimate rather than today's pump number.
The table below scales the EPA's number to three common driving patterns. The combined MPG and the reference fuel price stay constant, only the annual mileage changes. To get a current-prices estimate, take your local gas price and multiply by 652.2 gallons (the car's annual consumption at the rated MPG).
| Driving pattern | Estimated annual fuel cost |
|---|---|
| Light driver, 7,500 miles per year | $1,500 |
| Average driver, 15,000 miles per year | $3,000 |
| Heavy driver, 25,000 miles per year | $5,000 |
Year-over-year MPG for the Audi S4
The EPA has rated the Audi S4 across 26 model years, from 1992 Audi S4 through 2025 Audi S4. The numbers below are the best combined MPG figure the EPA published for each year, which lets you see when the car was at its most efficient and how recent generations stack up.
The 1992 Audi S4 returned 18 MPG. The most recent 2025 Audi S4 returns 24 MPG. That is an improvement of 6 MPG over 33 model years, the kind of gain that usually comes from smaller engines, hybrid systems, or aerodynamic redesigns.
| Year | Combined MPG | Open year page |
|---|---|---|
| 2025 | 24 MPG | 2025 Audi S4 |
| 2024 | 24 MPG | 2024 Audi S4 |
| 2023 | 24 MPG | 2023 Audi S4 |
| 2022 | 24 MPG | 2022 Audi S4 |
| 2021 | 23 MPG | this page |
| 2020 | 23 MPG | 2020 Audi S4 |
| 2019 | 24 MPG | 2019 Audi S4 |
| 2018 | 24 MPG | 2018 Audi S4 |
| 2016 | 21 MPG | 2016 Audi S4 |
| 2015 | 21 MPG | 2015 Audi S4 |
| 2014 | 21 MPG | 2014 Audi S4 |
| 2013 | 21 MPG | 2013 Audi S4 |
| 2012 | 21 MPG | 2012 Audi S4 |
| 2011 | 21 MPG | 2011 Audi S4 |
| 2010 | 21 MPG | 2010 Audi S4 |
| 2008 | 16 MPG | 2008 Audi S4 |
| 2007 | 16 MPG | 2007 Audi S4 |
| 2006 | 16 MPG | 2006 Audi S4 |
| 2005 | 16 MPG | 2005 Audi S4 |
| 2004 | 18 MPG | 2004 Audi S4 |
| 2002 | 18 MPG | 2002 Audi S4 |
| 2001 | 18 MPG | 2001 Audi S4 |
| 2000 | 18 MPG | 2000 Audi S4 |
| 1994 | 18 MPG | 1994 Audi S4 |
| 1993 | 18 MPG | 1993 Audi S4 |
| 1992 | 18 MPG | 1992 Audi S4 |
Compare against other Compact Cars for 2021
If you are cross-shopping the 2021 Audi S4, the most useful comparison is against the other cars in the Compact Cars class for the same model year. The list below shows the highest-MPG peers, ranked from most to least efficient. Click any of them to open its full page.
The Kandi K27 leads this group at 114 MPG, 91 MPG ahead of the 2021 Audi S4.
Specifications
The 2021 Audi S4 runs a 3-liter 6-cylinder turbocharged engine paired with a automatic (s8), sending power through all-wheel drive.
Engine, transmission, and drivetrain together drive most of the variation in fuel economy across trims. A larger engine moves the car with less effort but burns more fuel. A turbo lets a small engine punch above its weight, often without much MPG penalty. All-wheel drive adds traction and weight, and usually costs a couple of MPG compared with two-wheel drive of the same engine.
- Vehicle class
- Compact Cars
- Engine
- 3L 6-cylinder turbocharged
- Transmission
- Automatic (S8)
- Drivetrain
- All-Wheel Drive
- Fuel type
- Premium
- Annual petroleum use
- 12.9 barrels per year
- Start-stop system
- Yes
Common questions about the 2021 Audi S4
Quick answers to the questions people most often search for when looking up the 2021 Audi S4.
-
Is the 2021 Audi S4 fuel efficient?
Not particularly. The 2021 Audi S4 returns 23 combined MPG, which trails the average car in the Compact Cars class for the same model year by about 23%. -
What MPG does the 2021 Audi S4 get?
The EPA rates the 2021 Audi S4 at 23 combined MPG, 20 MPG in city driving, and 28 MPG on the highway. Real-world numbers depend on your driving style, the weather, and how loaded the car is. -
How much does it cost to fuel a 2021 Audi S4 per year?
The EPA estimates an annual fuel cost of $3,000 for the 2021 Audi S4. That figure assumes 15,000 miles of driving per year, a 55% city and 45% highway split, and the EPA's published average fuel price for the rated fuel grade. -
Does the 2021 Audi S4 require premium gas?
Yes. The EPA lists the 2021 Audi S4 as requiring premium gasoline. Running it on regular can reduce performance and may affect engine warranties, so it is not a recommended way to save at the pump. -
Has the Audi S4 become more fuel efficient over time?
Yes. The first EPA-rated Audi S4, the 1992 Audi S4, returned 18 combined MPG. The most recent 2025 Audi S4 returns 24 MPG, an improvement of 6 MPG over the run. -
How much CO₂ does the 2021 Audi S4 emit?
Tailpipe CO₂ emissions are 380 g/mi. Multiplied across a typical year of driving (15,000 miles) that works out to about 5,700 kilograms of CO₂. -
What is the difference between the city and highway MPG of the 2021 Audi S4?
City driving returns 20 MPG and highway driving returns 28 MPG, a gap of 8 MPG. A spread that wide is typical of cars with conventional automatic or manual transmissions, where stop-start city traffic eats more fuel than a steady highway cruise. -
What engine is in the 2021 Audi S4?
The 2021 Audi S4 has a 3-liter 6-cylinder turbocharged engine (EPA description: SIDI). -
What transmission and drivetrain does the 2021 Audi S4 have?
The 2021 Audi S4 comes with a automatic (s8) transmission and all-wheel drive. All-wheel-drive variants typically read 1 to 3 MPG lower than the front-wheel-drive equivalent of the same engine, since the extra hardware adds weight and parasitic loss. -
How does the 2021 Audi S4 compare to the best car in its class?
The most efficient car in the Compact Cars class for the 2021 model year is the Kandi K27 at 114 combined MPG. The Audi S4 returns 23 MPG, a gap of 91 MPG. If you are comparing on fuel economy alone, the class leader is worth a look.
Source: U.S. EPA fuel economy dataset. Annual fuel cost figures assume 15,000 miles of driving per year and a 55% city, 45% highway split. Real-world mileage varies with driving conditions, vehicle maintenance, fuel quality, and driver behaviour.