Review: Audi B9 RS4 (2018-on)

Overview

The Audi B9 RS 4 Avant is a high-performance, compact executive wagon. To be manufactured in Ingolstadt, Germany, the all-wheel drive Audi B9 RS 4 will be powered by a 2.9-litre biturbo V6 petrol engine that is mated to an eight-speed automatic transmission. Australian deliveries of the Audi B9 RS 4 are expected to commence in the second quarter of 2018.

2.9 TFSI biturbo V6 engine

Shared with the Audi F5 RS 5 Coupe , the 2894 cc V6 engine is understood to have an aluminium alloy crankcase and cylinder head, thin-walled grey cast iron cylinder liners, aluminium pistons, double overhead camshafts (chain-driven), four valves per cylinder, variable intake and exhaust valve timing, variable intake valve lift, two turbochargers – one for each cylinder bank – that are positioned within the engine’s ‘V’ and direct injection.

To achieve a higher compression ratio and avoid knock (i.e. uncontrolled detonation), the TFSI biturbo engine has a shorter compression phase relative to the expansion phase. According to Audi, the valvelift system enables shorter intake valve opening times under part loads by closing the intake valves early. At higher loads, however, the inlet valves are actuated via a camshaft contour that provides a longer opening time and larger valve stroke to maximise engine power.

The Audi B9 RS 4 Avant can accelerate from rest to 100 km/h in 4.1 seconds and has an electronically limited top speed of 250 km/h (280 km/h with the optional RS dynamic package). Over the combined NEDC test cycle, fuel consumption is 8.8 litres per 100 km.

quattro all-wheel drive system

The four-wheel drive ‘quattro’ system for the Audi B9 RS 4 is a mechanical system which utilises a self-locking central differential (designed as a planetary gear train). In normal conditions, the differential delivers 60 per cent of the engine’s torque to the rear axle and 40 per cent to the front, i.e. a 40:60 front:rear torque split. Depending on the situation, however, up to 70 per cent of the engine’s torque can be transferred to the front and up to 85 per cent to the rear.

Wheel-selective torque control and sport differential

As standard, the Audi RS 4 has ‘wheel-selective torque control’. During ‘dynamic cornering’, wheel-selective torque control brakes the front and rear inside wheels to prevent wheelspin and improve turn-in.

As an extra-cost option, the Audi RS 4 can be specified with a rear ‘sport differential’ that distributes torque between the rear wheels via two superposition gears. In this process, a software function integrated into the central chassis control unit continuously computes the ideal torque split. When turning into or accelerating in a curve, most of the torque is directed to the outside wheel to generate yaw and reduce understeer.

Body and dimensions

The Audi B9 RS 4 Avant is underpinned by Volkswagen AG’s MQB platform. Compared to the Audi B8 RS 4 Avant , the Audi B9 RS 4 Avant is 62 mm longer (at 4781 mm), 16 mm wider (1866 mm), 12 mm lower (1404 mm) and has a 13 mm longer wheelbase (2826 mm). Furthermore, the Audi B9 RS 4 Avant weighs 1790 kg.

Relative to the Audi B9 A4 , changes for the B9 RS 4 Avant include 30 mm wider wheel arches which have ‘quattro blisters’ for added emphasis, an RS-specific rear diffuser insert, oval tailpipes and a roof edge spoiler.

Suspension

The Audi B9 RS 4 has five-link front suspension in which the upper links are integrated into the bodywork and the lower links are attached with rubber mounts to a hybrid steel/aluminium sub-frame. For the five-link rear suspension, the axle is insulated from the body by hydraulically damped axle mounts. To reduce mass, the axle links, pivot bearings and damper stilts are made of forged aluminium. Compared to the Audi B9 A4 , the suspension of the B9 RS 4 Avant is 7 mm lower.

As an extra-cost option, the Audi RS 4 can be specified with Audi’s ‘Dynamic Ride Control’ (DRC). With DRC, diagonally-opposed pairs of shock absorbers are linked by hydraulic lines and a central valve. When cornering at speed, the valves regulate oil flow within the shock absorber of the deflected outside front wheel almost immediately, providing greater support and reducing lateral lift. DRC also includes three selectable damping settings: comfort, auto and dynamic.

Steering

The Audi B9 RS 4 has electromechanical power steering in which the level of power assistance was inversely proportional to vehicle speed. As an option, the Audi B9 RS 4 is available with ‘dynamic steering’ which varies its ratio – by up to 100 per cent – according to the vehicle speed, steering angle and the mode selected in the ‘Audi drive select driving-dynamics’ system.

Safety equipment

Standard safety equipment for the Audi B9 RS 4 includes dual front airbags, front seat-mounted side airbags, full-length curtain airbags (i.e. for front and rear occupants), ABS, electronic brake force distribution, brake assist, electronic stability control, traction control and front seatbelts with pre-tensioners and load limiters.

As standard, the Audi B9 RS 4 is expected to be fitted with:

• ‘Audi pre sense city’: operating at speeds up to 85 km/h, Audi pre sense city uses a windscreen-mounted front camera to scan the road for other vehicles and pedestrians. If there is a risk of a collision, the driver receives a series of warnings. If the driver fails to respond, full braking force is applied autonomously. At initial speeds of up to 40 km/h, collisions can be prevented; at higher speeds (up to 85 km/h), the severity of the collision is reduced;
• Audi pre sense front: an extension of ‘Audi pre sense city’, pre sense front operates at speeds up to 250 km/h and can prevent front-to-rear collisions or reduce their severity. In hazardous situations, the driver receives visual and acoustic warnings to apply the brakes, followed by a brief application of the brakes for a jolting effect to alert the driver. If the driver fails to respond, the RS 4 decelerates to the greatest possible extent if the vehicle ahead of it is still moving;
• ‘Audi pre sense rear’: can warn of potential collisions from behind, warn following traffic by rapidly flashing the brake lights and activate the ‘Audi pre sense basic’ protection measures described below;
• ‘Audi pre sense basic’: initiates occupant protection measures such as tightening the front seatbelts, closing the windows and sunroof (where fitted), and activating the hazard lights when ‘unstable driving conditions’ are detected;
• Adaptive Cruise Control (ACC): using two front radar sensors and the camera, ACC can maintain a specified distance – from five distances – between the RS 4 and the vehicle ahead. Furthermore, ‘Audi drive select’ can be used to adjust the rate of acceleration and other control dynamics;
• Stop&Go function: an extension of the ACC, ‘Stop&Go’ operates at speeds of 60 km/h to apply the brakes and bring the vehicle to rest. Once traffic begins moving, the Audi RS 4 automatically accelerates;
• Traffic jam assistant: as part of the ACC, the Traffic jam assistant provides automated steering if traffic is congested and vehicle speeds are below 65 km/h;
• Audi side assist: operating at speeds above 15 km/h, Audi side assist uses two rear radar sensors to monitor traffic up to 70 metres behind the RS 4. If another vehicle approaches quickly or is in the driver’s blind spot, a warning LED in the housing of the appropriate door mirror illuminates. If the driver activates the indicator to change lanes, the LED blinks rapidly to warn the driver;
• Audi active lane assist: uses the front camera to detect lane markings at speeds of 65 km/h and above. If the Audi RS 4 approaches a lane marking without the driver having previously indicated, the electromechanical steering provides an adjustment to bring the vehicle back into its lane. Using the MMI system, the driver can determine whether this system should be active at all times or only before the lane marking is crossed. As an option, the driver can choose to have steering wheel vibrations as a warning signal;
• Collision avoidance assist: activated when the RS 4 needs to avoid an obstacle to avert a collision. Using data from the front camera, the ACC and radar sensors, ‘avoidance assist’ can calculate the distance of the car ahead, its width and degree of offset. The brakes are then briefly applied to alert the driver of the potential danger and, once the driver starts steering, the system provides ‘support with the necessary lane changes with controlled interventions to the power steering’;
• Rear cross-traffic assist: when reversing at low speeds, rear cross-traffic assist uses the rear radar sensors to detect approaching traffic. If approaching traffic is detected which may cross the vehicle’s path, the driver receives warnings (visual, acoustic and a brief, jolting application of the brakes);
• Turning assist: active at speeds from 2 km/h to 10 km/h, ‘turning assist’ operates once the driver activates the right-hand turn signal (for RHD vehicles) and can monitor oncoming traffic. In hazardous situations, the brakes are applied to bring the vehicle to rest;
• Exit warning: activated when the vehicle stopped moving, ‘exit warning’ warns occupants if vehicles are approaching from behind by illuminating red fibre optics in the door-opening mechanism as the doors are opened;
• Multi-collision brake: after a collision, multi-collision brake provides ‘controlled application of the brakes’ to reduce vehicle speed and reduce both the likelihood and severity of subsequent collisions;
• High beam assist: automatically switches between low and high beam headlights for improved visibility, using a sensor to determine when it is safe to do so (i.e. without dazzling other drivers); and,
• Attention assist: monitors driver behaviour and issues a warning if the driver is assessed to be ‘inattentive’.

The Audi B9 RS 4 also has an ‘active bonnet’ which deploys pyrotechnic charges in the event of a pedestrian collision to raise the height of the bonnet and locks it in position to provide clearance over ‘hard points’ in the engine bay. In doing so, the likely severity of the pedestrian’s impact is reduced.

Euro NCAP testing

In Euro NCAP testing , the related Audi B9 A4 received a five star safety rating which included a 90 per cent adult occupant protection rating and an 87 per cent child occupant protection rating. In the frontal offset test, protection of the driver’s head, thighs and feet were rated as good, though lower leg protection was rated as adequate and chest protection as marginal.

Features: Audi B9 RS 4 Avant

Standard features for the Audi B9 RS 4 Avant are expected to include 19-inch forged alloy wheels, a 180 watt sound system which has ten speakers, a subwoofer and six-channel amplifier, digital radio tuner (DAB+), MMI navigation plus which included a seven-inch high-resolution colour display with 3D maps, integrated voice control, live traffic updates, a CD/DVD player, two SDXC card readers and 10 GB flash memory for media storage, ‘Audi connect’ (in-car Wi-Fi hotspot), Bluetooth interface with music streaming, ‘Audi music interface’ with two USB inputs and auxiliary input socket, Audi smartphone interface for Apple or Android smartphone integration, power adjustable front sports seats with pneumatic adjustment of the side bolsters, driver’s seat massage and memory functions, Fine Nappa leather upholstery, three-zone climate control air conditioning, cruise control with braking, LED headlights with LED daytime running lights, dusk-sensing headlights, rain-sensing wipers, a leather wrapped steering wheel with gearshift paddles, 40:20:40 split and folding rear seats, remote central locking with proximity key, push-button start, power adjustable and heated door mirrors with folding function, kerb view function for the passenger side door mirror on reverse, an auto-dimming interior rear view mirror, power windows, a height and reach adjustable steering wheel, map lights, ambient lighting, tyre pressure loss indicator, floor mats, rear privacy glass, a trip computer and an immobiliser.

As standard, the Audi B9 RS 4 will be fitted with Audi’s ‘virtual cockpit’, a configurable 12.3-inch high-resolution colour display in place of the instrument cluster. The Audi RS 4 will also be equipped with the ‘Audi parking system plus front and rear’ which consists of front and rear parking sensors, a surround view camera system which provides a 360 degree view of the vehicle, and a visual display.

Related links

• Audi Media: the new Audi RS 4 Avant (September 2017)