Audi Sport GmbH has fine-tuned many details of the RS 4 Avant which was newly introduced in September 2017, including the addition of a new high-torque twin-turbo V6 with a power output of 331 kW (450 metric hp) and 600 N·m (442.5 lb-ft) of torque to the crankshaft in a broad engine speed range from 1,900 to 5,000 rpm.
With the 2.9 TFSI twin-turbo V6, Audi Sport GmbH is building on the legendary 2.7 liter V6 of the first RS 4 Avant from 1999. Back then, the twin-turbo V6 had a power output of 279 kW (380 metric hp). The new RS 4 Avant now outputs 331 kW (450 metric hp), which equals an output of 155.5 metric hp per liter. This allows the RS 4 Avant to accelerate from zero to 100 km/h (62.1 mph) in just 4.1 seconds.
The TFSI engine weighs just 182 kilograms (401.2 lb), which is 31 kilograms (68.3 lb) less than the V8 engine in the predecessor model from 2012. This benefits the gross weight and the axle load distribution—two prerequisites for the impressive performance. The RS dynamic package increases the electronically governed top speed from 250 to 280 km/h (155.3 to 174.0 mph).
The two turbochargers of the 2.9 TFSI are each assigned to a cylinder bank and build up a boost pressure of up to 1.5 bar. Like with all V6 and V8 engines from Audi, the turbochargers are installed within the 90-degree interior “V” of the cylinder banks, and thus the exhaust side of the cylinder heads is on the inside, while the intake side is on the outside of the engine.
This layout enables compact construction and short gas flow paths with minimal flow losses, allowing the 2.9 TFSI to respond particularly spontaneously to movement of the accelerator pedal.
In the new WLTP driving cycle, the engine consumes 9.2 liters of fuel per 100 kilometers (25.6 mpg US), which corresponds to 208 grams of CO2 per kilometer (334.7 g/mi). This constitutes a consumption reduction by 17% as compared to the previous model.
A decisive factor in this efficiency is the new TFSI combustion process from Audi, which is known as the B-cycle (earlier post). It has been specifically designed for the partial-load range, which is the predominant operating mode during normal use.
In the case of higher loads and rotational speeds, the two-stage Audi valvelift system (AVS) closes the intake valves later, thereby increasing the opening duration to a crank angle of 200 degrees. Simultaneously, valve lift increases from 6.0 to 10 millimeters (from 0.2 to 0.4 in). The cylinder charge thereby increases accordingly—the engine revs up powerfully and delivers an opulent output.
The power of the 2.9 TFSI flows to the quattro permanent all-wheel drive system via the sporty eight-speed tiptronic. In regular driving, the system delivers more power to the rear axle. Its purely mechanical center differential directs 60% of the torque to the rear axle and 40% to the front. If undesired slip occurs at one axle, most of the power is automatically and rapidly redirected to the other axle—up to 70% to the front or up to 85% to the rear axle. The high locking values enable a clearly defined torque distribution and highly precise interaction with the control systems of the ESC and wheel-selective torque control.
The driver can create a personal driving experience via the standard Audi drive select dynamic handling system. There are five profiles available: comfort, auto, dynamic and the customizable, RS-specific RS1 and RS2 modes. The Audi drive select dynamic handling system influences the engine and transmission management, the power steering, the suspension, the dynamic steering, the quattro sport differential, the engine sound and the characteristics of the automatic air conditioning. The customizable RS2 mode exists specifically to influence the Electronic Stabilization Control (ESC) quickly at the push of a button.
The RS 4 Avant will make its debut at the DTM finale at the Hockenheimring on 4 to 6 October 2019. Sales in Germany and other European countries will start in October 2019. The new RS 4 Avant will be at dealerships as of December 2019. Prices for the high-performance Avant start at €81,400.