Under German watch and Europe’s hyper-aggressive emissions laws, there’s no encore for naturally aspirated V-8s revving to kingdom come. As we witness Mercedes-Benz AMG euthanizing its big-bore 6.2-liter V-8, and BMW M GmbH replace the old M3’s 4.0-liter V-8 with a 3.0-liter twin-turbo straight-six, we must ask: what of Audi? Sadly, it too is swapping its free-breathing eight-cylinder for a forced-induction six-cylinder in some applications.

We’ve learned from deep within Audi that the next RS4 will trade its 450-hp, 4.2-liter V-8—the same mad mill as found in the RS5—for a turbocharged V-6. While plucking the 3.0-liter supercharged V-6 from Audi’s armada of S cars would seem the most logical choice, Quattro GmbH is instead shifting focus to turbos for its RS-branded models. We suspect Audi will affix a pair of turbochargers to the six-cylinder, which would allow the brand to trump the 430 horsepower of BMW’s new M4 and M3. Whether Audi will bring the RS4 or its new turbo six-cylinder to America is still undetermined.

This wouldn’t be the first time Quattro gave its RS4 a turbo six. During the 2000 and 2001 model years, Audi released an RS4 Avant with a 375-hp, 2.7-liter twin-turbo V-6 tuned by Cosworth, but only for Europe.

Audi knows the 4.2-liter V-8’s instant throttle response and 8500-rpm redline are huge selling points to simply throw away, but the brand’s been in the process replacing V-8s with V-6s for some time. The S4, S5, and A6 all were available with eight-cylinder power as recently as 2011. We haven’t missed those eight-cylinders as much as we’ve enjoyed the improved fuel economy and greater low-end torque from the new blown sixes. So long as Quattro maintains the RS4’s crackling exhaust, there won’t be time for a eulogy.

The heart of the S models is a newly developed V6 engine with petrol direct injection and turbocharging. The 3.0 TFSI has an output of 260 kW (354 hp); its 500 Nm (368.8 lb‑ft) of torque is available across a wide range of speeds from 1,300 to 4,500 rpm. The engine outstrips its predecessor in terms of power and torque, while simultaneously offering significantly lower fuel consumption and weight.

The engine can accelerate the Audi S4 from 0 to 100 km/h (0 to 62 mph) in 4.7 seconds, and the electronic limiter kicks in at 250 km/h (155.3 mph). Despite its considerably improved performance, the V6 is extremely efficient. In the NEDC cycle, the S4 Sedan consumes less than 7.4 liters of fuel per 100 kilometers with 170 grams CO2 per kilometer (31.8 US mpg [273.6 g/mi]).

The new eight-speed tiptronic transmission is highly efficient and provides fast, comfortable and spontaneous gear changes. Whenever the driving situation allows, it switches to freewheeling to save fuel.

As on every Audi S model, the power of the 3.0 TFSI is transmitted to the road by quattro permanent all-wheel drive. During normal driving, the selflocking center differential funnels 60 percent of engine torque to the rear axle and 40 percent to the front. Depending on the operating situation, it can distribute up to 70 percent to the front axle or up to 85 percent to the rear. The wheel-selective torque control based on an intelligent software function rounds off the quattro drive train. For dynamic cornering, the wheels on the inside of the bend are slightly braked before they can slip. This makes handling more precise, agile, and stable. A sport differential available as an option improves the handling further by actively distributing the forces between the rear wheels.

Intelligent dynamics: suspension

The new Audi S4 and S4 Avant handle corners of all kinds with aplomb – whether on a racetrack or a mountain pass. For fast motorway driving, both models feature impressive straight-line stability. This performance is down to the newly developed suspension. The five-link suspension on the front and rear axle precisely separates the longitudinal and transverse forces, thus ensuring optimum handling in all driving situations. Like the electromechanical power steering, both are designed to be very lightweight. Variable speed-dependent dynamic steering is available as an option.

The standard S sport suspension is 23 millimeters (0.9 in) lower than on the basic model. The ride height is the same with the optional suspension with active damper control. Along with the engine, steering, tiptronic and sport differential, CDC dampers (CDC = continuous damping control) are included in the Audi drive select handling system which comes as standard. This enables the driver to adjust the suspension characteristics in several modes.

The standard 18 inch wheels in 5‑twin-spoke star design roll on 245/40 size tires. A 19‑inch alternative is available from quattro GmbH. Powerful, stable brakes are fitted on the large wheels.

Sporty understatement: design

The appearance of the new S4 models is subtly understated. At the front, the Singleframe grille and the accentuated horizontal lines underline the width. The bumpers and air inlets are prominently profiled. Many of the add-on parts are painted in finely graduated matt gray tones, accentuated with chrome trimming at selected points.

The exterior mirror housings in aluminum look are a visual highlight on the clear flowing side lines of the 4.74 meter long S4 (15.6 ft). The strongly profiled sill trims also give both models a striking appearance. On the tailgate, a separating edge provides targeted aerodynamics. The S‑specific rear bumper integrates a black honeycomb grille, an S‑typical diffuser clip, and the four tailpipes of the dual-branch exhaust system. Intelligent composite construction characterizes the body. This makes it exceptionally torsionally rigid, safe, and lightweight. It is the basis for the low unladen weight of the car. The sedan with quattro drive as standard tips the scales at 1,630 kilograms (3593.5 lb), the Avant at 1,675 kilograms (3692.7 lb).