The Audi S4, a performance-oriented version of the Audi A4, has a rich history of combining luxury with thrilling driving dynamics. A key element in achieving this performance has been the use of turbochargers. So, when did Audi introduce turbocharging to the S4? Let's dive into the history of the Audi S4 to uncover the answer.

The First Generation Audi S4 (1991-1994): A Turbocharged Start

The original Audi S4, produced from 1991 to 1994, was indeed turbocharged. This first-generation S4, known internally as the C4, featured a 2.2-liter 20-valve inline-5 cylinder turbocharged engine. This engine, designated as the AAN, produced an impressive 227 horsepower and 258 lb-ft of torque. The turbocharger played a crucial role in boosting the engine's output, providing a significant increase in power compared to naturally aspirated engines of the time. The C4 S4 was available as both a sedan and an Avant (wagon), offering practicality alongside its performance capabilities. The turbocharged engine was paired with a 5-speed manual transmission or an optional 4-speed automatic transmission, and it featured Audi's renowned quattro all-wheel-drive system as standard. This combination of turbocharging and all-wheel drive made the C4 S4 a formidable performer in various driving conditions. The C4 S4 set the stage for future generations of the S4, establishing a reputation for blending performance with everyday usability. Its turbocharged engine was a key differentiator, providing a level of power and responsiveness that was uncommon in its class. The success of the C4 S4 paved the way for Audi to continue exploring turbocharging technology in its future performance models. The C4 S4 remains a sought-after classic among Audi enthusiasts, appreciated for its unique engine, turbocharged performance, and timeless design. Its place in Audi's history as the first S4 model and its use of turbocharging make it a significant milestone for the brand.

The Second Generation Audi S4 (1997-2001): Twin Turbos Arrive

The second-generation Audi S4, known as the B5 (produced from 1997 to 2001), continued the tradition of turbocharging, but with a significant upgrade. Instead of a single turbocharger, the B5 S4 featured a 2.7-liter twin-turbo V6 engine. This engine, designated as the AGB or AZB depending on the market, produced 261 horsepower and 295 lb-ft of torque. The use of two smaller turbochargers, one for each bank of cylinders, helped to reduce turbo lag and improve throttle response. This resulted in a more linear and predictable power delivery, enhancing the driving experience. The B5 S4 was available as a sedan and an Avant, offering the same blend of performance and practicality as its predecessor. The twin-turbo V6 engine was paired with a 6-speed manual transmission or a 5-speed automatic transmission, and it also featured Audi's quattro all-wheel-drive system as standard. The B5 S4 was widely praised for its performance capabilities, with many publications noting its impressive acceleration and handling. The twin-turbo engine provided a significant improvement in performance compared to the previous generation, making the B5 S4 a popular choice among enthusiasts. The B5 S4 also became a popular platform for aftermarket modifications, with many owners increasing the engine's output through tuning and other upgrades. The B5 S4's twin-turbo engine cemented Audi's commitment to turbocharging as a means of enhancing performance. The success of the B5 S4 further solidified the S4's reputation as a performance-oriented vehicle that could be enjoyed every day. The B5 S4 remains a highly regarded model among Audi enthusiasts, appreciated for its twin-turbo performance, timeless design, and tuning potential.

The Third Generation Audi S4 (2003-2008): A Brief Hiatus from Turbocharging

The third-generation Audi S4, the B6 and B7 models produced from 2003 to 2008, took a different approach to performance. Instead of using a turbocharged engine, the B6 and B7 S4 models featured a 4.2-liter naturally aspirated V8 engine. This engine, producing 340 horsepower and 302 lb-ft of torque, offered a different kind of driving experience compared to the turbocharged models. The naturally aspirated V8 provided a smooth and linear power delivery, with a distinctive exhaust note. While the B6 and B7 S4 models were still very capable performers, the lack of turbocharging was a notable departure from the previous generations. The decision to use a naturally aspirated V8 was likely influenced by a desire to offer a different driving experience, as well as by the availability of a suitable V8 engine within the Audi lineup. The B6 and B7 S4 models were available as a sedan, Avant, and Cabriolet, offering a wider range of body styles than the previous generations. The naturally aspirated V8 engine was paired with a 6-speed manual transmission or a 6-speed automatic transmission, and it also featured Audi's quattro all-wheel-drive system as standard. While the B6 and B7 S4 models were well-received, some enthusiasts missed the turbocharged performance of the earlier generations. The B6 and B7 S4 models represent a unique chapter in the S4's history, showcasing a different approach to performance. The naturally aspirated V8 engine provided a distinct driving experience, but the absence of turbocharging was a notable change.

The Fourth Generation Audi S4 (2009-2016): Supercharging to the Rescue

The fourth-generation Audi S4, the B8 and B8.5 models produced from 2009 to 2016, saw a return to forced induction, but with a twist. Instead of using a turbocharger, the B8 and B8.5 S4 models featured a 3.0-liter supercharged V6 engine. This engine, producing 333 horsepower and 325 lb-ft of torque, combined the benefits of forced induction with the responsiveness of a naturally aspirated engine. The supercharger provided instant boost, eliminating the turbo lag that can sometimes be associated with turbocharged engines. The B8 and B8.5 S4 models were available as a sedan and an Avant. The supercharged V6 engine was paired with a 6-speed manual transmission (until 2012), a 7-speed S tronic dual-clutch transmission. and it also featured Audi's quattro all-wheel-drive system as standard. The B8 and B8.5 S4 models were praised for their performance, handling, and overall refinement. The supercharged engine provided a significant improvement in performance compared to the previous generation, making the B8 and B8.5 S4 models a popular choice among enthusiasts. The supercharged V6 engine offered a unique driving experience, combining the responsiveness of a naturally aspirated engine with the power of forced induction. The B8 and B8.5 S4 models represent a successful return to forced induction for the S4, showcasing the benefits of supercharging technology.

The Fifth Generation Audi S4 (2017-Present): Turbocharging Returns

The fifth-generation Audi S4, the B9 model produced from 2017 to the present, marks a return to turbocharging. The B9 S4 features a 3.0-liter turbocharged V6 engine, producing 349 horsepower and 369 lb-ft of torque. This engine combines the latest turbocharging technology with advanced engine management systems to deliver impressive performance and efficiency. The turbocharger helps to boost the engine's output, providing strong acceleration and a wide powerband. The B9 S4 is available as a sedan and an Avant. The turbocharged V6 engine is paired with an 8-speed automatic transmission, and it also features Audi's quattro all-wheel-drive system as standard. The B9 S4 has been praised for its performance, handling, technology, and overall refinement. The turbocharged engine provides a significant improvement in performance compared to the previous generation, making the B9 S4 a top contender in its class. The return to turbocharging for the B9 S4 demonstrates Audi's commitment to using the latest technology to enhance performance and efficiency. The B9 S4 represents the latest evolution of the S4, combining turbocharged performance with advanced technology and luxurious features.

In conclusion, the Audi S4 has a long and storied history with forced induction. The first-generation S4 was turbocharged, as is the current model. The second generation S4 also featured turbocharging, but the third generation went without it, opting instead for a naturally aspirated V8. Then the fourth generation went for supercharging. So, to answer the question directly, the Audi S4 was first turbocharged in 1991 with the C4 model. With the current B9 model, Audi has returned to its turbocharged roots, delivering impressive performance and efficiency.