The 2018 Audi S4 sport compact sedan has evolved from its "look at me" heyday in the 1990s. It's not more serious about its looks and performance, with enough room and tech features to calm down when its not carving corners.
The S4 earned a 7.4 on our overall scale, which is very good for a new car. Its performance and standard features are impressive and it keeps pace with similar offerings from BMW and Mercedes-Benz. (Read more about how we rate cars.)
Style and performance
The Audi S4 has been given a thorough once-over like the related (mostly) two-door S5. Unlike the S5, the S4 only comes in one smartly styled shape.
Like the A4 before it, the S4 is sharpened from the last generation, with a lower nose and raised headlights, and sharper creases along the sides. The hood’s shunt lines are hidden by a deeply pressed crease in the body panels and helps the S4 achieve a more serious look. Standard LED headlights help frame the car’s arrival; wispy, but pronounced, boomerang lights look better than their S5 counterparts.
Along the sides, the S4 gets a deeper crease in the body that doesn’t read big under showroom lights, but does on the road. With just a bright disk in the sky projecting one source of light overhead (aka the sun), the S4’s body line casts a bigger shadow along the profile that allays our concern that Audi stylists were lazy (or, perhaps lazier).
The S4’s interior is subdued, with the same hewn approach as the outside. Deep comfortable buckets are accented by diamond-quilting patterns; the door inserts are shod with Alcantara and red contrast stitching; the instrument panel and center console are streamlined with available carbon-fiber inlays.
Spending more on an S4 gets more interior features but regardless of trim, the S4 is powered by a new turbocharged 3.0-liter V-6 that produces 354 horsepower and 369 pound-feet of torque. The single twin-scroll turbocharger is planted between the cylinder banks to feed both sides, but will feed one bank first to reduce turbo lag. In our testing, we found that it works; the S4 never feels out of breath. It rockets the S4 up to 60 mph in 4.4 seconds, which is quicker than the BMW 340i and Mercedes-AMG C43.
The new turbo V-6 benefits from Audi's long history with forced induction. Turbo lag has been quelled to hardly register with the driver's right foot—most of the available torque comes on at 1,350 rpm—and the acceleration is brisk and drama-free.
The S4 is all automatic this time around. An 8-speed automatic, related to the gearbox found in the RS 7, is the only partner available for the turbo-6. Although it rips off confident shifts, paddle-shifting the 8-speed isn’t especially precise or quick—the transmission will automatically shift at redline, manual mode or not. Regardless of selected drive mode, the S4 is eager to upshift to save fuel, unless you’re deep into the throttle.
Like previous generations, the S4 comes with standard all-wheel drive, which Audi calls Quattro. The 40/60, front-to-rear torque split is performance focused and keeps the car in shape while cornering. Grip isn’t easily given up, and when it does the S4 will politely chide drivers back into shape—no wild slides here.
Four-wheel independent suspension is standard, and a revised five-link setup up front has been cast out of more lightweight aluminum to reduce unsprung mass. Adaptive dampers are available on the S4 for the first time and drop the ride height by nearly an inch. Setting the dampers from Comfort to Dynamic stiffens the car, but we’d stop short of calling the S4 stiff. Each ride select setting—Comfort, Dynamic, Auto, and Individual—is closer to comfort than outright performance. It’s clear the S4 is meant to be a better all-rounder this time around.
A newly available sport rear differential—the first time it’s been offered on the S4 and the second-generation unit from Audi— shifts power side to side on the rear wheels, in addition to front-to-back duty that’s handled by the standard center differential. The rear differential makes the S4 a competent performer on the track, but it's also bundled with a sport steering setup that we'd like to tame.
Although the dynamic ratio clearly quickens with more speed, its feeling through the wheel is somewhat unpredictable. Dial in the steering, and the S4 is eager to keep things comfort-first with a slow ratio, but the performance ledge approaches quickly and the end result can leave the sedan feeling a little too darty. We don't think many drivers will notice unless that exuberance bites back, but we'd just like a little more progressiveness in the variable ratio.
Comfort, safety, and features
The S4 earns a slight edge over the mechanically related S5 due to slightly better packaging and a better driving position. The S4 is a true five-seater—6-footers can sit behind other 6-footers—and the addition of two doors made for better entry and exit into the second row.
Up front, comfortable sport buckets are complemented by standard seat massagers and are widely adjustable. In back, the two outboard positions don’t have the same bolstering as front seat riders, but are comfortable. Riding hump in the S4 may be a dicey proposition depending on how aggressive the driver is—be sure to call “shotgun” first.
The S4 features standard 60/40-split folding rear seats that supplement the trunk’s standard 13 cubic feet of cargo capacity.
Ride quality in the S4 falls closer to “comfort” than “performance,” which our backs appreciated after a long day behind the wheel. Audi doesn’t pipe in many engine sounds, and the rumble from quad-tipped exhausts out back is fairly muted too. The S4 doesn’t scream “sport sedan,” which may help explain part of its appeal.
Like the S5, it’s hardly likely that the S4 will ever be subjected to official crash tests. In the absence of data, we can draw from the related A4, which was named a Top Safety Pick by the IIHS.
The S4 comes equipped with “Pre sense city” advanced safety as standard equipment that was rated as “Superior” by the IIHS. Blind-spot monitors, parking sensors, and a surround-view camera system are optional extras, but thankfully a rearview camera is standard.
The rest of the S4’s standard feature list is impressive too. All versions of the S4 get sport buckets with a diamond-quilted pattern, front seat massagers, automatic climate control, Bluetooth connectivity, 18-inch wheels with summer 245/40 summer tires, LED headlights, leather seating with Alcantara inserts on the doors, a 7.0-inch driver information screen and a 7.0-inch infotainment screen is standard with Audi’s MMI interface.
A word about MMI: It runs Audi's native infotainment system very well with its clickwheel. Plug in a smartphone and prepare to run iOS or Android with chopsticks. It's frustrating and hard to use. We wish Audi would offer a touchscreen by now, but we can't have nice things.
Among the S4’s options list, we have our faves. The rear sport differential and adaptive suspension for $2,500? Check. Technology package that transforms the S4’s interior with “Virtual Cockpit” that includes a 12.3-inch driver information cluster and an upgraded 8.3-inch infotainment screen? Check. Navarra blue paint for $575? Check again.
Pinching pennies? Skip the $1,150 sport steering (too finicky), $500 warm weather package (heated seats are standard and the heated steering wheel doesn’t have a flat bottom), and bigger wheels.
At $51,875 to start for a Premium Plus model the S4 isn’t exactly budget car buying. We get that. But after riding in a $54,000-ish A4 loaded to the gills, and a tastefully optioned S4 at just over $59,000 we felt like the latter felt like a $60,000 car—the former seemed like a stretch.
If you’re looking for fuel-efficient driving, the S4 will hardly satisfy. The EPA rates the S4 at 21 mpg city, 30 highway, 24 combined.
- 2018 Mercedes-Benz C Class
- 2018 BMW 3-Series
- 2018 Cadillac ATS
- 2018 Lexus IS
The Audi most often competes against the BMW 3-Series and Mercedes-Benz C Class—specifically the 340i and C43, respectively. We'll concede that the Audi is faster, but the C43 and 340i are more enjoyable to drive, they're more visceral cars. The styling on the C43 is somewhat divisive, and the BMW is just old at this point, but the Audi S4 stops short of delivering a knockout to either one. The S4 beats the BMW on tech, but stops just short of beating the C43—we'd prefer a touchscreen to Audi's MMI. The Cadillac and Lexus are both outliers in this race, neither offer a direct competitor but have refreshing approaches to luxury compact cars available.