2021 Audi S4

Overview

Building on the athletic bones of the A4 sedan, the 2021 Audi S4 dials up some excitement with more power and more aggressive suspension tuning than the base A4 sedan offers. The S4 comes solely with a gutsy 349-hp turbocharged V-6, standard all-wheel drive, and a crisp-shifting eight-speed automatic transmission. Although it's quick, competent, and easy to drive fast, the S4 remains cooly distant; it lacks the feel and driver engagement of some of our favorite sports sedans, such as the Alfa Romeo Giulia, the BMW M340i, and the Mercedes-AMG C43. The Audi charms in different ways, though, and technophiles will likely gravitate to the S4's slick infotainment features while those who value modern design will appreciate the sedan's crisp styling and well-packaged cabin.

What's New for 2021?

Audi has made few changes to the S4 for 2021. All models now come standard with lane-departure warning and a built-in toll-road payment transmitter. The base Premium model's Convenience package now includes a heated steering wheel and parking sensors while the mid-range Premium Plus gains adaptive cruise control, lane-keeping assist, and a 360-degree exterior camera system. Top-flight Prestige models now offer heated rear seats as standard.

Pricing and Which One to Buy

Engine, Transmission, and Performance

All S4s ship with a 349-hp turbocharged 3.0-liter V-6 that syncs with an eight-speed automatic transmission and Quattro all-wheel drive. While the version we tested was quicker than most rivals, the engine response and exhaust sound—both hugely important characteristics of a sports sedan—were less visceral than expected. Despite its subdued engine character and lack of manual transmission, the V-6 delivered substantial thrust on demand, seamlessly transitioning between relaxed and responsive. Also impressive was its automatic gearbox, which had reactions that seemed so perceptive, we found the desire to shift for ourselves was virtually eliminated; well, almost. Looking at the numbers, the S4 ranks above most competitors in performance. Still, the experience lacks the emotion and sharp handling responses of top rivals. Its chassis is its greatest strength, with tautly controlled body motions and compliant damping that make it equal parts sports and luxury sedan. The S4 is very precise and easy to control; its accurate steering, excellent cornering stability, and tenacious grip on the tarmac boosted our confidence to torpedo on-ramps—but it also cruised calmly around town. Although the brakes were tremendously responsive, they were touchy at city speeds. The fluctuating feedback also interrupted the fun on curvier sections of road where the brake pedal could feel too soft.

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Fuel Economy and Real-World MPG

The S4 sedan is expected to earn 20 mpg in the city and 28 on the highway. Once we test it on our 75-mph highway fuel-economy route, which is part of our extensive testing regimen, we can evaluate its real-world mpg. For more information about the S4's fuel economy, visit the EPA's website.

Interior, Comfort, and Cargo

Audi is a benchmark of interior quality, and the S4 is further evidence of this. Every cabin is trimmed with marvelous materials and standard features such as diamond-stitched sports seats with massage features. Along with impeccable fit and finish, the interior is racy and luxurious. The flat-bottomed steering wheel, straightforward controls, and highly adjustable seat provide an exceptional driving position. The S4 had the quietest interior in our test, which also contributed to its calm demeanor—for better or worse. Despite having a 13-cubic-foot trunk—tied for smallest in its class with the Mercedes-AMG C43 sedan—the S4 held an impressive number of carry-ons. While its interior storage is average, the sedan can store a variety of loose items and personal belongings provided that they're not too big. Compared with the Infiniti Q50 Red Sport 400, the Audi is a much better travel companion. We only wish the S4 had a more versatile center console.

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Infotainment and Connectivity

Audi fits every S4 with a 10.1-inch center infotainment screen and ample infotainment options. Along with standard Apple CarPlay and Android Auto integration, the MMI system we tested responded quickly to commands and had user-friendly controls. While it's within the driver's line of sight, certain areas of the display require leaning forward to reach. Unfortunately, the S4 no longer includes a rotary controller on the center console, which helped make the system easier to navigate.

Safety and Driver-Assistance Features

The S4 has not been crash-tested by either the Insurance Institute for Highway Safety (IIHS) or the National Highway Traffic Safety Administration (NHTSA). The sports sedan does include several standard driver-assistance features, but other options such as adaptive cruise control and lane-keeping assist are only offered on the more expensive Prestige model. Key safety features include:

• Standard automated emergency braking with forward-collision warning
• Available blind-spot monitoring with rear cross-traffic alert
• Available adaptive cruise control

Warranty and Maintenance Coverage

The S4 has an ordinary warranty that aligns with most competitors, but doesn't include any complimentary scheduled maintenance.

• Limited warranty covers four years or 50,000 miles
• Powertrain warranty covers four years or 50,000 miles
• No complimentary scheduled maintenance

More Features and Specs