The fastest Audi S4 to date is the post-facelift B9.5 variant, model years roughly 2020 and later, which offers the most horsepower in the S4 lineup.
How the S4 lineup has evolved and what makes the latest version fastest
To understand which year holds the speed crown, it helps to review how Audi evolved the S4 across its generations. Each redesign brought more power or refined performance characteristics, culminating in the current high-end S4 versions that sit at the top of the horsepower chart. Below is a concise chronology of the major S4 generations and their typical power figures, noting that exact numbers can vary by market and transmission choice.
Below is an overview of the key Audi S4 generations and their approximate power profiles. This list highlights the evolution that leads to the current fastest model.
- B5 S4 (1997–2002): 2.7L twin-turbo V6, roughly 340 hp (about 250 kW).
- B6 S4 (2001–2004): 4.2L naturally aspirated V8, roughly 340–344 hp.
- B7 S4 (2005–2008): 4.2L V8, roughly 340–344 hp.
- B8 S4 (2009–2016): 3.0L supercharged V6, about 333 hp.
- B9 S4 (2017–2020): 3.0L turbo V6, about 349–354 hp depending on market.
- B9.5 S4 (2020–present): 3.0L turbo V6, about 349–354 hp depending on market; the latest facelift represents the peak horsepower in the S4 family.
In summary, the modern, post-facelift S4s deliver the most power in the lineup, making the B9.5 the fastest stock Audi S4 on offer as of the early 2020s. For enthusiasts seeking even more speed, aftermarket tuning or moving up to higher-tier models like the RS4 would be the next steps, though that changes the model category entirely.
Why the latest S4s are faster (in stock form)
The leap in the current generation comes from a refined turbocharged V6, updated electronics, and transmission refinements that improve the drivetrain’s responsiveness. Audi’s emphasis with the B9.5 refresh was to extract more usable power and smoother delivery while maintaining daily drivability. Market-specific tuning also means horsepower figures can vary slightly between North American and European versions.
Notes on performance figures and scope
Factory performance numbers such as horsepower and 0–60 mph times can differ based on options, drivetrain (rear-wheel drive versus quattro all-wheel drive), and the presence of the dual-clutch or automatic transmission. Real-world performance can also be influenced by vehicle weight, tires, and weather conditions. For most buyers, the latest S4 offers the quickest stock acceleration within the S4 family, with additional gains possible through authorized tuning or performance packages.
Summary
The current, post-facelift S4—the B9.5 variant launched around 2020—holds the title for the fastest stock Audi S4, thanks to its higher peak horsepower (approximately 349–354 hp depending on market). If you measure speed by horsepower and latest technology in a factory-delivered package, the 2020s S4 models are the peak. For those seeking even more speed, aftermarket tuning or stepping up to higher-performance Audi models would be the next option.