The 2021 Audi S3 sedan continues with the same two trims, as the previous model year, which is Premium and Premium Plus. The Premium starts at $47,545 while the Premium Plus is priced at $52,935. The Premium trim, despite being the base trim, is fitted with tonnes of goodies, as listed below. The Premium Plus trim adds some niceties to the base trim. 

Besides these, Audi offers an S Sport package that garnishes the sport luxury sedan with red-painted brake calipers and an adaptive suspension. Limited to the Premium Plus, some packages add sport seats, adaptive cruise control, integrated navigation, and the Virtual Cockpit, a slick fully digital instrument cluster.

Which Trim should you buy?

The 2021 Audi S3 sedan in the Premium base trim, offers all the niceties that should be apt for cruising in the city rush or flying off at highway speeds. The ample number of creature comforts would please the occupants, but we’d advise adding the S Sport package to add adaptive suspension for configurable ride quality and handling.

The 2021 Audi S3 sedan retains the 2.0L turbocharged inline-4 powerhouse and it still cranks out exciting 288-horses and 280 lb-ft of torque. The 4-pot banger in the S3 sedan has been shared with the potent Volkswagen Golf-R hatchback. The engine is punchy and growls like a vexed beast at its redlines. It’s smooth and relaxed in leisure runs, and can be aggressive as well when the Audi S3 tries to launch off the standstill. A 7-speed S Tronic dual-clutch transmission and standard Quattro all-wheel-drive aids in repeating the same powerful and sporty run every time.

About the same, the 2021 Audi S3 sedan sprints from 0-60 mph in just 4.3 seconds while it munches the quarter-mile in just 11.7-seconds. There’s slight turbo lag as the pedals are pressed from a standstill, but when the pace picks up, the Audi flies off, making the rivals eat its dust. The S Sport suspension offers agile handling to the luxury sedan. 

The 2021 Audi S3 sedan’s 4-pot is one of the powerful engines in the lot, while the Infiniti Q50 tops the chart with the best figures. The Audi has the best performance numbers, while the Infiniti comes closest with its run time of 5 seconds. The Alfa and the Merc take 5.3 seconds and 5.7 seconds respectively to reach the 60 mph mark. The Audi S3 offers the highest top speed as well.

How well does the 2021 Audi S3 Sedan handle?

The 2021 Audi S3 sedan acquits itself from boring and relaxed driving dynamics to agile and thrilling. Behind the steering, the driver will appreciate the sticky tires, slightly stiff suspensions, and Quattro all-wheel-drive that aspires confidence to take quick corners. Upgrading to Audi’s adaptive suspension adds adjustable levels of comfort and sportiness. 

The 2021 Audi S3 sedan is a hoot, but isn’t the best driver’s car like Golf-R. The steering feedback has to be applauded, despite the presence of electric assist. Though the overall ride comfort is quite average, the suspension is on the firm side. This rattles the cabin on sharp road imperfections. 

Braking Performance

With upright performance, the 2021 Audi S3 sedan can be easily stopped with significantly sized braking rotors and four-wheel disc brakes. These assist the driver to bring the racy S3 sedan to a dead-stop with ease, despite the hefty 3461 lbs curb weight. 

Since the data is scarce, it's hard to compare the 2021 Audi S3 sedan’s braking performance to the rest of the rivals. But with the reputation that the German automaker holds in the industry, the S3 sedan can be trusted for the best braking performance in the competition. Infiniti Q50 stops the quickest from 60-0 mph in just 105 feet despite being heavy. The Merc takes a long 121 feet to stop. The Audi has the largest front rotor at 13.4 inches and the Mercedes has the largest rear rotor at 12.6 inches. 

Despite being a sporty luxury sedan, the 2021 Audi S3 sedan aspires to be an economical pick in the segment. The 2.0L Turbo inline-4 in the heart of the S3 punches out impressive power and promising fuel economy at the same instance. On best days, the S3 sedan can deliver a combined 25 mpg. A 14.5-gallon tank is also fitted to the luxury sedan, and it stocks enough fuel to last for 350-plus miles in a full tank. 

Comparing the fuel economy, the 2021 Mercedes Benz CLA 250 4Matic turns out to be the most efficient in the long run with its combined economy of 29 mpg. The Giulia comes next, with its economy of 27 mpg combined. The Audi S3 sedan is down next in line, with its combined economy of 25 mpg. The Infiniti Q50 is the least economical, but has a massive 20-gallon fuel tank that gives it the most range out of these four cars, at 440 miles combined. The Audi has the least range, at 362 miles combined.

The German automaker loves to flaunt the high-quality and opulent build quality of the 2021 Audi S3 sedan. The interiors have ample premium leather surfaces and minimalist design language, but it isn’t a visual treat compared to the plusher A3. The cabin welcomes the front seat occupants with airy headroom and legroom, while they are seated in supportive and relaxing seats with excellent side support. The eyes of the front passengers would appreciate the tasteful subtle dashboard design, with round air vents and well-padded surfaces. 

The flat-bottom steering inspires sportiness, while the materials used in various sections of the cabin are top-notch. In the rear, the seats are soft and squishy. The S3 sedan can push three passengers in the back, but it might lead to shoulders. Especially the one in the middle might feel trapped. The seats are wrapped with leather upholstery in either Black with Rock Gray contrast stitching or Magma Red with Anthracite contrast stitching. The 2021 Audi S3 sedan offers an uninspiring 10 cu-ft of cargo space. So make sure to pack light. 

The 2021 Audi S3 sedan’s interior space is not bad at all. However, the rivals offer a better interior space. The most front headroom and legroom is in the Infiniti Q50 at 40.2 inches and 44.5 inches. The Infiniti’s rear is also very spacious and offers the most shoulder room. The Mercedes offers the least rear space among these four. On the ground of cabin roominess, the S3 sedan offers ample legroom but is quite tight on headroom in the rear. The cargo capacity offered by the Infiniti is the most at 13.2 cu-ft. Some standout interior features on the Audi S3 are:

• Panoramic sunroof
• Dual-zone automatic climate control
• Ambient interior lighting
• Heated front seats
• Full leather upholstery
• Power-adjustable front seats(Premium Plus)
• Optional sport seats
• Optional Nappa leather

What’s there to keep you entertained?

The 2021 Audi S3 sedan features a 7-inch retractable MMI center information display screen, which can be controlled through the controller on the center console. The screen looks outdated to rivals where integrated screens are more admired. The infotainment includes HD radio, Bluetooth connectivity, an SDXC card slot with 32 GB of storage, SiriusXM with a 90-day trial subscription, both Android Auto and Apple CarPlay compatibility, and auxiliary audio inputs as standard. 

The base Premium trim features Audi’s standard 7-speaker sound system. But the Premium Plus upgrades to an outstanding 14-speaker Bang & Olufsen. The S3 can also be optioned with Audi’s advanced virtual cockpit that adds a massive 12.3-inch screen ahead of the driver. Infotainment features offered on the 2021 Audi S3 are:

• 7-inch MMI Display
• Apple CarPlay and Android Auto Integration
• Bluetooth
• Wi-fi Hotspot
• Navigation system and voice controls
• 14-speaker Audio system by Bang & Olufsen 

The 2021 Audi S3 sedan is an unchanged carryover from the previous year, yet it looks like one of the most dashing and handsome vehicles one can pick in this segment. The front look adds aggression with a massive grille, sleek headlights, and LED DRLs. The side stance flaunts some straight lines and excellent wheel design, and the commanding stance adds to the beauty of the Audi sedan. The S3 sedan features sleek taillamps and the quad round exhausts are the best highlights of the rear end. 

The smaller wheelbase and sharp lines impart sportiness on the 2021 Audi S3 sedan’s wide stance. It is one of the lighter vehicles in the lot, but the widest of them all. The Q50 is the heaviest of them all, weighing in at 3842 lbs. It also has the most length at 189.6 inches. Surprisingly, it is actually the narrowest car in this competition. The Alfa has the least ground clearance of them all. The short height of the S3 sedan imparts a classier attire but takes away important numbers from the interior headroom. Some exterior features on the S3 are:

• Unique S3 badging
• Panoramic sunroof
• 18-inch alloy wheels
• Quad round exhausts
• LED headlamps and tail lights
• Aluminum door sills

The 2021 Audi S3 sedan is carried over without any changes, and it retains the same robust structure and chassis as the previous model year. The 2020 model year had scored a near-perfect 5-star rating in the NHTSA conducted crash tests. The IIHS didn’t test the 2020 model year, but it has rated the A3 as Top Safety Pick in the year 2019, which also shares the same sturdy structure as the S3 sedan. Some safety features included in the 2021 Audi S3 sedan are:

• Automated emergency braking
• Tire Pressure Monitoring System
• Front and Rear parking sensors
• Blind-spot monitoring
• Adaptive cruise control
• Rear Cross Traffic Alert

2021 Audi S3 sedan vs 2021 Infiniti Q50

The 2021 Infiniti Q50 is that child in the classroom, that studies hard, still doesn’t score well. As a rival to the Audi S3 sedan, the Q50 is punchier but eats the dust in acceleration. The interiors are refined, but the buyers would find the S3 more luxurious and composed. The Infiniti Q50 tech bits are quite distinctive, yet pose as an outdated system.

2021 Audi S3 sedan vs 2021 Alfa Romeo Giulia

The 2021 Alfa Romeo Giulia is one of the best driver’s cars that balances an incredible powertrain with driver centric interior. But the Giulia is more spacious and more practical, provided it has an uncanny rear-seat room, which’s a whole lot better than in the Audi. In terms of interior niceties, the Audi S3 is better, with more refinement, more luxurious attire, and advanced tech bits.

2021 Audi S3 sedan vs 2021 Mercedes Benz CLA 250

The 2021 Mercedes Benz CLA 250 might be the least powerful luxury sedan in the lot, but it churns those figures the most efficiently. The efficiency will have you trade-off to brilliant acceleration punch, but in the case of the 2021 Audi S3 sedan, it’s lively yet somehow offers impressive economy, but not the best. Inside the cabin, the Mercedes Benz has an edge with a more opulent and refined cabin, and better gadgets in the segment.

Despite missing out on any upgrades or additions for 2021, the Audi S3 sedan is a brilliant package of outstanding acceleration punch, engaging driving with interior comfort and luxury. The handsome and stylish attires still prevail, until the 2022 S3 sedan comes with refreshed exterior. The powertrain is both punchy and reasonably efficient for its nature. The rivals are more adequate if interior refinement is a priority, and if you’re that tech-savvy person, the Mercedes Benz might please you.