The Audi RS 4 Avant quattro was unveiled at the 2012 Geneva Motor Show and was based on the B8 A4 Avant. The RS 4 Avant uses the Volkswagen MLB platform, and shares the same powertrain as the RS 5 Coupé. The RS 4 features larger bumper air dams and features double exhaust tailpipes compared to the S4's double twin (quadruple) exhaust tailpipes. Wider arches allow for a wider axle and wheels. A completely remodelled front bumper cover with honeycomb grill compared to the standard A4 and S4 as well as remodelled rear bumper with honeycomb detailing and minor air diffuser.
The interior is largely the same but the flat-bottom steering wheel is covered entirely in perforated leather with RS badging on the steering wheel and gear stick. The interior dashboard and door liners are also detailed with carbon fibre inserts as standard although there were options to change this to aluminium or piano black. SuperSport seats covered partly with leather part Alcantara were standard in the B8 RS 4 but as with the B7, there was a winged backed bucket seat option. It was also an option to order the seats covered entirely with leather. The RS 4 is powered by a 4.2L FSI V8 engine producing 450 PS (450 PS; 444 hp) and 430 N⋅m (317 lbf⋅ft) allowing the car to accelerate from 0–60 mph (0–97 km/h) in 4.7 seconds. The RS 4 Avant is available with a 7-speed dual-clutch S-Tronic transmission.
New for the B8 are 'wavy' vented and floating cast iron discs, 365 mm (14.4 in) diameter and 34 mm (1.34 in) thick, with 6-pot Brembo floating calipers, and at the rear 330 mm (13.0 in) by 22 mm (0.87 in) discs with a single-piston floating calliper.
The standard wheels were 19 inch alloys with 235/40 R19 Pirelli P-Zero performance tyres. Optional 20" rotor design or 10 spoke alloy wheels were also available with 265/35 R20 Pirelli P-Zero tyres.
A sports pack was available which included Sports exhaust identifiable by black exhaust tips in the rear bumper, Dynamic Ride Control (DRC) suspension. The Sports pack also came with the 20" rotor design wheels as standard.
The sports exhaust, DRC suspension setting, steering, engine response, engine mapping, and exhaust note are all adjustable using the 'Drive Select' feature which is a button on either the centre console or through the MMI display interface. Settings that can be selected are Comfort, Auto, Dynamic, or Individual with the Individual setting allowing the driver to select any of comfort, auto, or dynamic for a number of handling and performance options.