Behind the sharp suit and business-like styling, the new RS 4 hides a 4.2-litre V8 engine capable of launching the family estate car from 0-60mph in less than 5 seconds.
The Audi RS 4 Avant uses the same high-revving, naturally aspirated V8 engine found in the RS 5 Coupe. With its distinctive red-painted cylinder covers, the unit produces 444bhp at an ear-splitting 8,250 rpm and 430Nm of torque.
The RS 4 Avant van sprint from 0 to 62 mph in 4.7 seconds on its way to an electronically limited top speed of 155 mph, which can be increased to 174 mph if required.
That powerplant is mated to a dual-clutch transmission, which can be left to shift automatically or the driver can choose to change gears manually using either a selector lever or paddles on the steering wheel. There's also a launch control system, which manages the engagement of the clutch to achieve the fastest possible getaway with no wheel spin.
Compared to the standard A4 Avent, the RS 4 is 20 millimetres longer, 24 millimetres wider and sits 20 millimetres lower to the ground. It will be available in a choice of eight colours: one solid and one metallic finish, four pearl-effect colours and two special 'crystal-effect' colours: Panther Black, which is available from launch, and Prism Silver, which will be available to order later this year.
Being an estate, the RS 4 can easily accommodate the weekly shop, a couple of suitcases and a dog or two, while still sprinting to 60mph in less than five seconds.
Prices and an exact release date have yet to be announced, but Audi has said that the first cars will be delivered to UK customers by September.
Available exclusively in the Avant body style, and expected in the UK in September, the RS 4 portrays a distinctly business-like first impression - hiding the fact that this sensible estate can, with the electronic limiter removed, top 170mph.
The interior features a flat-bottom steering wheel not too dissimilar to that found on the Audi R8 supercar. While business-like black leather is the order of the day, deep and closely-fitting bucket seats hint at the car's wilder side.
Mobile phone integration and a sat-nav powered by Google Maps is included.
The beating heart of Audi's new RS 4 is a 4.2-litre V8 engine producing 444bhp and 430nm of torque which means a 0-60mph time of 4.7 seconds and a top speed of 155mph (174 with the limiter removed).
Despite the power, the RS 4 returns a respectable 25.7 miles per gallon, according to Audi.