Sport and luxury are showcased in the A4, Audi's best-selling sedan. The A4 has been in production since mid-1990s, and the current B9 generation went on sale for 2017. The car combines upscale materials, extensive technology, and AWD traction. More performance comes in the sporty S4, and the A4 Allroad wagon adds cargo capacity and some off-road capability.
Following a thorough refresh for 2020, the 2021 A4 receives a 13-hp increase and a 12V mild hybrid electrical system. Additionally, FWD is no longer offered; all A4 trims feature Audi's Quattro AWD system. Wireless Apple CarPlay, lane departure warning, and an integrated toll transponder are among upgrades to the revised standard and optional equipment mix.
Although the A4 isn't inexpensive, it's nonetheless a good value. The equipment and performance it provides is impressive for its price.
A finalist in MotorTrend's 2017 Car of the Year competition, the A4's spacious interior, dazzling tech, and nimble handling impressed. Less memorable was its styling, which struck us as regressive. The 2020 refresh sharpened some lines, but the A4 still looks similar to before.
In an eight-way comparison test among compact luxury sedans, the A4 finished second. Its performance numbers were strong, but it just wasn't as fun as the test-winning Alfa Romeo Giulia. Still, the A4's quality and features justified its relatively high price.
After over a year in our long-term test fleet, the A4 proved why it's one of the best cars in its class. Its roomy cabin and helpful driver-assist tech made it a great daily driver and road-tripper. Meanwhile, its strong turbocharged engine and snappy dual-clutch transmission made us smile on twisty backroads. The A4 would benefit from more personality, but it's eminently capable.
We love a good wagon here at MotorTrend, but the A4 Allroad delivers a mixed experience. Its features, technology, and performance are comparable to its sedan counterpart. But the lifted suspension that gives it all-road capability results in a sometimes bouncy ride. The A4 Allroad's main quandary is Audi's own Q5 crossover, which offers more cargo and interior room for a lower starting price.
The S4, Audi's iconic compact performance sedan, has attributes to suit diverse preferences. As the "S" suggests, it's sporty and entertaining, but it falls short of pure racy focus. That's a worthwhile tradeoff for its comfort, which matches other A4 variants. Agile fun or subdued relaxation are a flick of the drive mode selector away.
All A4 variants (except the S4) are powered by a 2.0-liter turbo-four engine, which routes output through a seven-speed dual-clutch transmission to Audi's Quattro AWD system. For 2021, this engine's power increases by 13 hp and gains a 12V mild-hybrid electrical system. Quattro is now standard on all models; previously the entry-level A4 was FWD.
The entry-level A4, badged 40 TFSI, produces 201 hp and 236 lb-ft of torque. MotorTrend has not tested the A4 40 TFSI in AWD form, but 0-60 mph acceleration should take about 6.7 seconds. Expect fuel economy to come in at about 26/33 mpg city/highway.
In the A4 45 TFSI, engine output measures 261 hp and 273 lb-ft of torque. Based on MotorTrend's testing of earlier A4 models, 0-60 mph acceleration will likely take approximately 5.0 seconds. Fuel economy for this A4 should match the 2020 model's 24/32 mpg. The A4 Allroad shares its engine with the A4 45 TFSI.
Sportiness is enhanced in the S4 thanks to its turbocharged 3.0-liter V-6 engine. Unchanged for 2021, it produces 349 hp and 369 lb-ft of torque. Unlike four-cylinder A4 models, the S4 uses an eight-speed automatic transmission but retains AWD. We tested a 2018 S4 hitting 60 mph in only 4.2 seconds. Fuel economy falls to an EPA-rated 20/27 mpg.
Audi's A4 coupe is called the A5. The two share key mechanical components, but the A5 wears more dramatic styling that enhances its two-door sleekness, whether in hardtop or convertible form.
Except the A5 isn't only a two-door—Audi also makes a four-door hatchback variant called the A5 Sportback that blurs the boundaries between coupe and sedan. Regardless, equipment and powertrains are essentially identical between the A4 and A5, and the S4 and S5. However, Audi offers a super-sporty RS 5, while there's no RS 4 sold in the U.S.
All A4 models include forward collision warning and automatic emergency braking, which Audi calls PreSense City. Available driver-assist and active safety features include lane departure warning, lane keep assist, blind-spot monitoring, side and rear cross-traffic alert, and adaptive cruise control.
Based on crash safety scores for the 2020 A4, the 2021 model should perform well. The 2020 A4 earned a five-star (out of five) overall safety score from the NHTSA, which factors five-star side crash and rollover scores with a four-star frontal crash score. From the IIHS, the 2020 A4 received top Good scores in all crashworthiness tests. Its standard and optional front-crash prevention systems also got the highest Superior score, as they stopped fully in 12-mph tests, and reduced speed by 22 mph in 25-mph tests for vehicle-to-vehicle automatic braking. All A4 models also came to a full stop in all crossing pedestrian tests.
The A4's trunk has 12.0 cubic feet of cargo space, with standard 40/20/40 split folding rear seats helping larger items fit inside. In the front row, headroom measures 37.3 inches, which compares to 38.7 inches in the BMW 3 Series. Front legroom is 41.3 inches in the A4, a bit less than the 3 Series' 42.0 inches. The Audi's second-row headroom of 37.4 inches is close to the BMW's 37.6. There's a bit more rear legroom in the A4, at 35.7 inches to the 3 Series' 35.2.
The A4 Allroad wagon offers 24.2 cubic feet of space behind the second row, or up to 58.5 cubic feet with the second row folded. Headroom and legroom measurements in both rows are within a 0.1 inch of the A4 sedan.
Every 2021 A4 uses a 10.1-inch infotainment touchscreen loaded with Audi's slick MIB 3 user interface. For 2021, wireless Apple CarPlay is added, with Android Auto, Bluetooth streaming, and an integrated toll transponder also included. Two front-row USB ports are standard, with two second-row ports and a wireless charging pad added on Premium Plus and Prestige trims. A 7.0-inch gauge cluster display is fitted on Premium models, while higher-end A4s get a 12.3-inch all-digital gauge display. Built-in GPS is included on Prestige models and optional on others. The standard audio system has 10 speakers, and a 19-speaker Bang & Olufsen premium setup is available.
All A4 trim levels are available with the 40 TFSI or 45 TFSI engine. Choosing 45 TFSI adds the sport-inspired S Line exterior appearance package.
Exterior: 17-inch alloy wheels, LED headlights and taillights, heated power-adjustable side mirrors, heated windshield washer nozzles, sunroof, metallic exterior trim, dual-exhaust outlets
Interior: Leather seating upholstery, heated power-adjustable front seats, 7.0-inch gauge cluster display, 10.1-inch infotainment display, dual front-row USB ports ambient lighting, 10-speaker audio system
Convenience: Three-zone climate control, one-touch up/down power windows, push-button start, automatic high beams, automatic windshield wipers
Exterior: 18-inch alloy wheels, headlight daytime running lights, auto-dimming power-folding side mirrors
Interior: Leatherette armrest and console trim, 12.3-inch digital gauge cluster display, wireless charging pad, dual second-row USB ports
Convenience: Keyless entry with hands-free trunk opening, adaptive cruise control, lane-keep assist, 360-degree view parking camera system, cellular signal enhancer, side and rear cross-traffic alert, front and rear parking sensors, driver's seat memory settings
Exterior: Upgraded LED headlights, headlight and taillight animation, headlight washer nozzles, dual-pane acoustic front windows
Interior: Head-up display, multi-color ambient lighting, heated rear seats, 19-speaker audio system
Convenience: Built-in navigation, traffic sign recognition
Exterior: 18-inch 10-spoke alloy wheels, headlight daytime running lights, sport front and rear bumpers, quad exhaust outlets
Interior: Diamond-stitched leather/faux suede seating surfaces, power-adjustable sport front seats
Exterior: Adds auto-dimming power-folding side mirrors
Exterior: Adds upgraded LED headlights, headlight and taillight animation, headlight washer nozzles, dual-pane acoustic front windows
|$0||1.49% Financing available for varying term lengths : 36, 48, 60 Months - Audi announces APR rates on select models.||02-01-2021|
|$0||1.99% Financing for a maximum term of 66 Months - Audi announces APR rates on select models.||02-01-2021|
|$0||2.49% Financing for a maximum term of 72 Months - Audi announces APR rates on select models.||02-01-2021|
|$0||2.99% Financing for a maximum term of 75 Months - Audi announces APR rates on select models.||02-01-2021|
|$500||Audi announces a Bonus cash for customers who Finance through Audi Financial Services using AFS Standard or Special rates. [Regional Incentive. See dealer for availability.]||02-01-2021|
|$500||Audi announces an Audi Credit that is good towards cash purchases, outside lenders or AFS Standard Lease or Standard APR rates. [Regional Incentive. See dealer for availability.]||02-01-2021|
|$750||Audi announces a Lease Bonus cash for customers who Lease or Premier Purchase through Audi Financial Services using AFS Standard or Special rates. [Regional Incentive. See dealer for availability.]||02-01-2021|
|$750||Audi announces an Audi Credit that is good towards cash purchases, outside lenders or AFS Standard Lease or Standard APR rates.||02-01-2021|