Review: Mercedes-Benz V177 A-Class (2019-on)

Overview

Released in Australia in May 2019, the Mercedes-Benz V177 A-Class was a compact sedan. Manufactured in Rastatt, Germany, the Mercedes-Benz V177 A-Class Sedan range initially consisted solely of the A 200 model which was powered by 1.3-litre turbocharged four-cylinder engine (see table below). The range, however, was subsequently expanded with the A 180 (August 2019) and A 250 (late 2019). All models were fitted with seven-speed dual clutch transmissions (DCTs) that were produced by Getrag.

4MATIC all-wheel drive system

The ‘4MATIC’ all-wheel drive system for the Mercedes-Benz V177 A 250 4MATIC included:

• A power take-off unit to the rear axle that was integrated into the dual clutch transmission; and,
• A multi-plate clutch that was integrated into the rear axle differential and electro-mechanically controlled (previously electro-hydraulically actuated).

In normal conditions, the engine’s torque was directed to the front wheels for maximum fuel efficiency. If, however, there was a loss of traction or such a loss was anticipated, then the electric motor exerted an axial force on the clutch pack – via a crown wheel and a ball ramp – to close the clutch plates so that 50 per cent of the engine’s torque was directed to the rear wheels (i.e. a 50:50 front:rear torque distribution). The advantages of this control system were:

• Non- rpm-dependent operation across the entire actuation range;
• Pilot control of the clutch while stationary; and,
• Higher efficiency due to the ball ramp concept.

Furthermore, the rear axle differential compensated for the different paths/rotational speeds of the rear wheels.

Body and dimensions

The V177 A-Class was underpinned by Mercedes-Benz’s MFA2 compact car platform. Compared to the Mercedes-Benz W177 A-Class Hatch, the V177 A-Class Sedan was 130 mm longer (at 4549 mm) and 6 mm lower (1434 mm), though width (1796 mm) and wheelbase length (2729 mm) were unchanged; boot space also increased by 60 litres to 420 litres.

With a frontal area of 2.19 m², the Merecdes-Benz V177 A-Class Sedan achieved a drag-coefficient of 0.22 Cd, the lowest ever measured for a passenger vehicle at the time of its release. Aerodynamic measures included:

• A two-section ‘Airpanel’ louvre system behind the radiator grille;
• Sealed headlamp surrounds;
• An aero lip in the bonnet’s joint to the front apron;
• Front and rear spoilers;
• Underbody panelling for the engine compartment, main floor and rear axle, and diffuser panels;
• For models with petrol engines, a specially shaped rear exhaust silencer and heat shield; and,
• ‘Aerodynamically optimised’ door mirrors, wheels and tyres.

Suspension

The Mercedes-Benz V177 A-Class Sedan had MacPherson strut front suspension with a forged aluminium transverse control arm and tie-rod for each wheel. Furthermore, the MacPherson struts had transverse force-optimised coil springs and twin-tube gas-pressure shock absorbers with auxiliary springs.

The V177 A-Class Sedan was designed with two different rear suspension systems –

• The A 180 and A 200 models had a torsion beam rear axle in which the U-section rotated in one-sided compression and rebound, and acted as a stabiliser bar. The torsion beam rear axle was secured to the body by two bearings; and,
• The A 250 4MATIC models had four-link rear suspension – consisting of three transverse arms and one trailing arm for each wheel – mounted on a sub-frame that was isolated from the bodyshell by rubber bushings.

Both rear suspensions had single-tube shock absorbers and separate coil springs. Furthermore, noise insulation of the coil spring between the body and rear axle was achieved with two elastomer insulators.

As an option, the Mercedes-Benz V177 A-Class Sedan was available with electronically controlled damping (‘active damping control’) whereby a valve in each of the four shock absorbers was electronically actuated to control oil flow and therefore damping characteristics. As such, damping was stiffened during acceleration, braking or steering manoeuvres to reduce pitch and body roll. In conjunction with ‘Dynamic Select’, the driver could also select from ‘comfortable’ or ‘sporty’ damper settings.

Steering

The Mercedes-Benz V177 A-Class Sedan had rack-and-pinion steering with speed-sensitive electric power assistance; the steering wheel required 2.6 turns from lock to lock. The electric servo unit could also assist driver steering movements that were intended to ‘stabilise’ the vehicle by generating additional steering torque – these included:

• Counter-steering in the event of oversteer;
• Steering corrections when braking on varying road surfaces;
• Reducing the steering effects of front-wheel drive; and,
• Compensation for crosswinds and road camber.

Safety equipment

Standard safety equipment for the Mercedes-Benz V177 A-Class Sedan included dual front airbags, a driver’s knee airbag, front seat thorax-pelvis side airbags, full-length curtain airbags, ABS, electronic brake force distribution, brake assist, electronic stability control, traction control and front seatbelts with pre-tensioners and load limiters.

The Mercedes-Benz V177 A-Class Sedan was equipped with camera and radar systems that could perceive up to 500 metres ahead of the vehicle. Fitted as standard, Active Brake Assist with cross-traffic function could mitigate the consequences of collisions with vehicles or pedestrians in front of the vehicle. If a collision risk was detected, the system initially issued a visual warning. If there was a serious risk of collision, the driver received an additional, audible warning and the required brake pressure to prevent a collision was calculated (if possible) so that it could be applied when the driver depressed the brake pedal. If the driver failed to respond, however, Active Brake Assist initiated autonomous emergency braking to mitigate or prevent the collision.

For Australia, the Mercedes-Benz V177 A-Class Sedan was fitted with the following active safety technologies as standard:

• Active Lane Keeping Assist: operating at speeds from 60 km/h to 200 km/h, Active Lane Keeping Assist warned the driver if the vehicle was unintentionally drifting out of its lane via pulsed vibrations through the steering wheel. If the vehicle crossed a continuous line, the system could pull the vehicle back into its lane by applying the brakes on one side of the vehicle. In the case of a broken line, such intervention would occur only when there was a collision risk with a vehicle in the adjacent lane (including oncoming traffic);
• Blind spot assist (passive): used two radar sensors in the rear of the vehicle to warn the driver before an indicated lane-change if a vehicle was in the driver’s blind spot;
• Exit Warning Assist: could issue a visual warning in the door mirror when the vehicle was stationary and up to three minutes after the ignition had been turned off to warn of an approaching vehicle or bicycle (providing it was exceeding 2 m/s). If the driver used the door handle at this moment, an additional acoustic warning would be issued;
• Crosswind Assist: could detect sudden, strong gusts of wind and prevent the vehicle from drifting out of its lane via corrective braking forces on one side of the vehicle;
• Pre-Safe Sound: would emit a brief rushing sound when a collision was imminent to trigger the stapedius muscle in the ear and reduce the risk of hearing damage;
• Attention Assist: monitored driver behaviour for signs of fatigue and, if detected, issued visual and audible warnings;
• Traffic Sign Assist: used navigation data and image recognition to display – in the instrument cluster – the maximum permitted speed, restrictions on overtaking and pedestrian warnings near ‘zebra’ crossings. Traffic Sign Assist also had an extended wrong-way warning, while the detection of stop signs was been combined with the ECO start/stop function so that the engine would remain on. Active Speed Limit Assist was a sub-function of Traffic Sign Assist that used the forward-facing camera to recognise sign gantries and road works signs to set the vehicle’s maximum speed; and,
• Pre-Safe Plus: used the rear radar sensors to detect if a rear-end collision was imminent and, if so, flashed the rear hazard lights and prepared occupant protection measures such as the seatbelt tensioners. If the vehicle was stationary and the risk of a collision persisted, the system could apply the vehicle’s brakes to reduce the risk of injuries by reducing the forward jolt caused by an impact from the rear.

As an extra-cost option, the Mercedes-Benz V177 A-Class Sedan could be specified with a ‘Driving Assistance Package’ which included the following –

• Active Distance Assist Distronic with Active Steering Assist: operating at speeds up to 210 km/h, the system could maintain a pre-set distance to the vehicle ahead. A stop-and-go function also enabled the vehicle to be braked until stationary, remain stationary for up to 30 seconds and then accelerate when the traffic ahead started moving. Active Distance Assist Distronic also combined navigation data with camera/radar inputs to adjust speed when approaching bends, junctions or roundabouts. Active Steering Assist helped the driver in keeping the vehicle in the centre of its lane by applying steering wheel torque, using lane markings for orientation at speeds up to 210 km/h and, at speeds up to 130 km/h, also used the position of vehicles ahead;
• Active Emergency Stop Assist: if it was detected that the driver was no longer actively driving the vehicle while it was moving, Active Emergency Stop Assist would bring the vehicle to rest within its lane. If there was no steering wheel movement over a longer period when Active Steering Assist (see below) was active, the system issued visual and audible prompts for the driver to place their hands on the steering wheel. If the driver failed to respond, vehicle speed was reduced until it was stationary. At speeds below 60 km/h, following traffic was warned by the hazard warning lamps;
• Evasive Steering Assist: operating at speeds from 20-70 km/h, Evasive Steering Assist could help the driver avoid a pedestrian that was detected by the radar sensors and stereo camera. If the driver initiated an evasive manoeuvre by turning the steering wheel, the system provided ‘precisely calculated steering torque to support the movement of the steering wheel’ to avoid the pedestrian and then straighten the vehicle;
• The Cross-Traffic Assist: could operate at speeds up to 72 km/h and used the stereo camera and radar sensors to detect traffic that was crossing in front of or behind the vehicle. If detected, the driver would receive visual and audible alerts;
• Active Lane Change Assist: operating at speeds from 80 km/h to 180 km/h, Active Lane Change Assist could perform lane changes – within 10 seconds – in response to the driver nudging the indicator stalk; and,
• Active Blind Spot Assist: at speeds from 12 km/h to 200 km/h, the system could provide a visual alert and audible alarm if there was a risk of a side collision when the turn indicator was actuated. As part of the Driving Assistance Package, the brakes on one side of the vehicle could be applied when travelling at speeds above 30 km/h to avoid a side collision.

The V177 A-Class Sedan had an ‘active bonnet’ which, in the event of a pedestrian collision, deployed pyrotechnical actuators to raise the height of the bonnet by around 80 mm to create additional clearance between the bonnet and components in the engine bay to reduce the risk of pedestrian injury.

Features: Mercedes-Benz V177 A 180 Sedan

Inside, the Mercedes-Benz V177 A-Class featured a new multimedia system called ‘Mercedes-Benz User Experience’ (MBUX) which could be operated by touchscreen, buttons on the steering wheel and a touchpad on the centre console and voice control with natural language comprehension (‘Linguatronic’). From June 2019 deliveries, the ‘Mercedes me Connect’ smartphone app enabled owners to remotely interact with their vehicle with functions such as remote door locking locking/unlocking, climate control settings and navigation.

For Australian-delivered vehicles, the Mercedes-Benz V177 A-Class had two 10.25-inch displays: one for the instrument cluster and one for the media touchscreen. The infotainment system included an HDD navigation system (NTG6 MB), an ‘Advanced Sound System’ which had nine speakers and a subwoofer with a total output of 225 watts, a digital radio tuner (DAB+), Bluetooth mobile phone connectivity and a USB-C connection.

Standard features for the Mercedes-Benz WV77 A 180 included 17-inch alloy wheels, ‘Comfort’ front seats in synthetic leather (‘Artico’) upholstery, climate control air conditioning (‘Thermatic’), cruise control, LED headlights with integrated LED daytime running lights, dusk-sensing headlights, rain-sensing wipers, front and rear parking sensors, a reversing camera with dynamic guidelines, a rear fog lamp, 40:20:40 split and folding rear seats, steering wheel gearshift paddles, remote central locking with proximity key (i.e. keyless entry), power adjustable mirrors with heating and folding functions, power windows, an automatically dimming rear-view mirror, push-button start, an electric park brake, ambient interior lighting, illuminated vanity mirrors, a 12 volt power socket (in the luggage compartment), black roof lining, tyre pressure monitoring, a trip computer and an immobiliser.

The Mercedes-Benz A 180 was also equipped with ‘Active Parking Assist’ which could identify suitable parallel parking spaces – when traveling at speeds of up to 35 km/h – and steer the vehicle into the parking space while the driver controlled vehicle speed.

Features: Mercedes-Benz V177 A 200 Sedan

Compared to the A 180 Sedan, the A 200 Sedan was further equipped with 18-inch alloy wheels, four-way adjustable electropneumatic lumbar support for the driver’s seat, through loading rear seats, wireless mobile phone charging and adaptive highbeam assist.

Brochure and specifications

• Specifications: Mercedes-Benz V177 A-Class Sedan (August 2019)
• Brochure: Mercedes-Benz V177 A-Class Sedan (June 2019)
• Technical Data: Mercedes-Benz V177 A-Class Sedan (May 2019)