There are two major differences. The first is of course the form factor; the second is where it will be sold. This is not an American proposition, so don't hold berate your local Audi dealer. If you want one, move to Europe after it goes on sale later this year.
This is a shame, but not a surprise. Audi is in the midst of slotting a CUV into every possible micro-niche it can find, including the upcoming Q2 that the company teased this week. Unfortunately, that means Americans will miss out on the sizable cargo area (17.8 - 53.3 cubic feet, compared to just 17 cu ft in the S4 sedan's trunk) and lower center of gravity when compared to a typical CUV.
If you want a S4 Avant here in the States, the closest you can get is the A4-based Allroad, which packs the familiar 2.0-liter TFSI engine and eight-speed auto. Too bad; the S4 Avant is a great-looking wagon.
Lightweight and strong: the 3.0 TFSI
The strong heart of the two new S models from Audi is a newly conceptualized 3.0 TFSI engine. The direct gasoline injection engine with turbocharging has an output of 260 kW (354 hp) and produces a hefty torque of 500 Nm (368.8 lb‑ft) from 1,370 to 4,500 rpm. In terms of power and torque, it surpasses the previous model while achieving considerably lower figures in weight and fuel consumption.
The turbo V6 engine accelerates the Audi S4 from 0 to 100 km/h (62.1 mph) in 4.7 seconds, and on up to an electronically governed top speed of 250 km/h (155.3 mph). The standard sprint takes two tenths of a second longer in the S4 Avant. In the NEDC cycle, the S4 Sedan only consumes 7.4 liters of fuel per 100 km (31.8 US mpg), which equates to less than 170 grams CO2 per kilometer (273.6 g/mi). The Audi S4 Avant has a fuel consumption of less than 7.5 liters per 100 km (31.4 US mpg), which equates to 175 grams CO2 per kilometer (281.6 g/mi).
Sporty and stable: handling
In the new S4 models, a fast and smoothly shifting eight-speed tiptronic handles power transfer. Their lower gears have short, sporty ratios, while the upper gears are long to reduce revs and fuel consumption. When the driver releases the accelerator pedal at a speed between 55 and 160 km/h (34.2 and 99.4 mph) the automatic transmission switches over to an efficient freewheeling mode.
The quattro permanent all-wheel drive makes a large contribution to the sporty handling of the S4 and S4 Avant cars. In normal driving, it distributes engine forces with a slight emphasis of the rear wheels – if necessary the majority of forces can be directed to the axle with better traction.
Torque vectoring optimizes handling and stability in fast cornering with minimal brake interventions. The optional sport differential actively distributes torque between the rear wheels.
The five-link front and rear suspensions enable significant comfort gains with emphatically sporty response. An alternative to electromechanical power steering is dynamic steering which varies its steering gear ratio according to the driving speed. 18‑inch wheels with size 245/40 tires are standard. Audi Sport also offers 19‑inch wheels. The front brakes have internally-vented and perforated discs that are 350 mm (13.8 in) in diameter. They are gripped by black (or optionally red) painted six-piston fixed calipers with S lettering.
The standard S sport chassis lowers the body's ride height by 23 mm (0.9 in) compared to the A4 base model. The same height applies to the optional chassis with damper control. The Audi drive select handling system integrates what is referred to as CDC (continuous damping control) dampers along with the engine, steering, tiptronic and optional sport differential. This lets the driver control the characteristics of the engine and chassis over several modes.
Comfortable and spacious: the interior
The new Audi S4 and S4 Avant seats five people comfortably. The horizontal lines of the instrument panel with its wide band of air vents convey an impression of generous width. The S4 Sedan offers 480 liters (17.0 cu ft) of luggage volume, and the S4 Avant offers from 505 to 1,510 liters (17.8 - 53.3 cu ft) depending on the positions of the rear seat backrests.
The optional S sport seats have integrated head restraints, adjustable lateral supports and a pneumatic massage function. The standard seat upholstery is fine Nappa leather in the colors black, rotor gray or magma red with diamond pattern, contrasting stitching and an S badge. The color black dominates in the interior, which is set off by contrasting inlays made of matt brushed aluminum.
A new top highlight is the optional Audi virtual cockpit that displays all key information digitally and in detailed graphics on its 12.3‑inch screen. Views available to the driver include a sport mode centered around the tachometer. In the new MMI operating system, the flat menu structure is based on that of today's smartphones, including intelligent free-text search. It suggests various search results after just a few letters have been entered. In addition, user operation is possible from the multifunction steering wheel or by natural language voice control.
State-of-the-art: infotainment and Audi connect
Infotainment in the new S models of the A4 model line is state-of-the-art. MMI navigation plus with MMI touch and an 8.3‑inch monitor top the infotainment range. MMI touch has a touchpad for zooming and scrolling and for entering characters. The system integrates the Audi connect hardware component, which connects the new S4 models to the internet via LTE. Passengers can use their mobile devices to surf the web, text or mail thanks to the integrated Wi-Fi hotspot. The driver meanwhile has access to the multifaceted online services offered by Audi connect. It is easy to control functions from a smartphone via the MMI connect app. The customer can lock or unlock the car doors, operate the optional auxiliary heater or find the parking location of the car in this way. The new Calendar service transfers the smartphone's calendar into the car.
The Audi phone box, another optional feature, connects smartphones to the on‑board antenna by near-field coupling and simultaneously charges them inductively according to the Qi standard. The Audi tablet serves as a flexible Rear Seat Entertainment device. For very discerning hi-fi fans, the Bang & Olufsen sound system with its new 3D sound is available. The Audi smartphone interface brings Apple Car Play and Android Auto into the car. If the customer connects an iOS or Android smartphone to the USB port (iOS from 7.1, Android from 5.0 Lollipop), the smartphone's contents such as navigation, phone, music and select third party apps are offered in a separate MMI menu. They can be accessed conveniently by MMI or voice control. Audi has designed both applications especially for use in the car. The core content here is online music with access to a large range of music from Google Play Music and iTunes. There are also navigation and notification functions as well as schedule reminders. In the future, the range of functions will be continually extended via third party apps like Pandora, Spotify and WhatsApp.
Leading role: driver assistance systems
The new Audi S4 and S4 Avant are right at the forefront in their class with a broad array of driver assistance systems. The systems come from the full-size class; their intelligent interplay represents the next step toward piloted driving.
The predictive efficiency assistant helps the driver save fuel. Adaptive cruise control maintains a specified distance to the vehicle ahead. The driver can set this distance and the control dynamics over several stages. Its Stop&Go function brakes the car to a full stop and lets it start off again automatically at the driver's request. Over a speed range from 0 to 65 km/h (40.4 mph), traffic jam assist – another function of ACC – can also take over steering on well-built roads, as long as the traffic is moving slowly. The rear cross traffic assist, exit warning, turn assist, obstacle avoidance assist and Audi pre sense systems further enhance safety.
Sporty understatement: exterior design
The appearance of the new S4 models is sporty but not ostentatious. The bumper, air inlets and side sills feature distinctive contours. Many of the add-on parts are painted in graduated tones of matt gray. Aluminum inlays accentuate its design. The exterior mirror housings shine in aluminum look. The rear bumper integrates a black honeycomb grille, aluminum diffuser trim and four tailpipes.
An intelligent combination of materials makes the bodies very torsionally stiff, safe and lightweight. The new S4 Sedan with standard quattro drive weighs just 1,630 kg (3,593.5 lb), while the new S4 Avant weighs 1,675 kg (3,692.7 lb) – 75 kg (165.3 lb) than the predecessor models.
Extensive: the equipment
The new S4 models from Audi arrive on the European market in summer 2016. Their extensive standard equipment includes LED headlights, LED tail lights with dynamic turn signal, 18‑inch wheels with S-specific design, front sport seats upholstered in an Alcantara/leather combination and a leather-trimmed 3‑spoke sport steering wheel with multifunction plus.
The S4 Avant adds an electric drive for the tailgate and a luggage compartment cover. Audi can deliver optional high-tech features such as sensor control for the luggage compartment, a head-up display and Audi Matrix LED headlights. The latter control the headlight beam so precisely that oncoming traffic does not experience any glare. Another new feature is reduced headlight glare on traffic signs. When the light falls on a very reflective traffic sign, it is dimmed by around one-third in that area.
The price for the S4 Sedan is 59,300 euros. The S4 Avant is available starting at 61,150 euros.