GLA 45 Sports Brawnier Exterior, Packs More Power for 2021

GLA 45 is powered by the newly-developed, turbocharged, four-cylinder M139 2.0-liter engine.

“The second generation of our very successful compact sports model is now complete. The GLA portfolio, in the form of the Mercedes-AMG GLA 45, now also includes our innovative four-cylinder turbo engine, so setting the benchmark in this segment. In addition, the new GLA 45 is not only significantly more dynamic, but also more practical in everyday use than its predecessor, thereby ensuring its appeal to a dynamic, leisure-oriented target group,” says Tobias Moers, Chairman of the Board of Management of Mercedes-AMG GmbH.

One new feature which makes a substantial contribution to the incomparable driving experience is the active, fully variable AMG Performance 4MATIC+ all-wheel drive: this system offers selective power distribution to the wheels on the rear axle via AMG TORQUE CONTROL. This means that the power is distributed to the left and right rear wheels flexibly and at different ratios, according to the current driving situation – resulting in optimized traction, whatever the road surface conditions and whatever the route. This is made possible by a redesigned rear axle differential featuring two multi-disc clutches, which selectively provide the flow of power to each individual rear wheel.

New Four-cylinder Turbo Engine 

The GLA 45 is powered by the newly developed M139 2.0-liter engine, the world’s most powerful turbocharged four-cylinder manufactured for series production. With 382 hp and 354 lb-ft of torque in the GLA 45, it boasts more power than its predecessor. The new, highly efficient engine is handcrafted on an innovative production line in Affalterbach, according to the “One Man, One Engine” principle.

The new compact performance SUV completes the sprint from zero to 60 mph in record time: the GLA 45 requires just 4.3 seconds est. to complete this task. The top speed is electronically limited to 155 mph. Apart from its impressive power measures, the new engine also impresses with its quick responses. To this end, the torque curve was carefully balanced (“torque shaping”): The peak torque of 354 lb-ft is available in a range of 4,750-5,000 rpm. With this setup the AMG engineers have achieved a power delivery similar to that of a naturally aspirated engine.

Intelligent Engine Design Details

The new engine excels with numerous intelligent design features. In contrast to the transversely mounted four-cylinder in the 35-series AMG models, this new engine has been turned around its vertical axis by 180 degrees. This change in position means that the turbocharger and the exhaust manifold are now positioned at the rear, on the side of the firewall when viewed from behind. The intake system is positioned at the front. This configuration allows the flattest possible and most aerodynamically advantageous front section design. Furthermore, the new arrangement allows for much improved air ducts with shorter distances and fewer diversions – both on the intake and exhaust side.

The new twin-scroll turbocharger combines optimized responsiveness at low engine speeds with high power in the upper rpm range. The shaft of the compressor and turbine wheel is mounted for the first time on anti-friction bearings, minimizing mechanical friction in the turbocharger. The turbocharger therefore responds quickly and reaches its maximum speed of up to 169,000 rpm rapidly. With a maximum charge pressure of 2.1 bar, the 2.0-liter four-cylinder turbo engine is also the leader in its segment in this respect. The electronically controlled wastegate (exhaust relief valve) allows the charge pressure to be controlled even more precisely and flexibly while optimizing responsiveness, especially when accelerating from partial load.

Two-stage Fuel Injection for Optimized Performance

For the first time, the new high-performance four-cylinder features two-stage fuel injection. In the first stage the particularly fast and precisely operating piezo injectors supply fuel to the combustion chambers at a pressure of up to 200 bar. This is controlled by the engine management system as required. In the second stage there is additional intake manifold injection using solenoid valves. This is needed to achieve the engine’s high specific output. The electronically controlled fuel supply has an operating pressure of 6.7 bar.

Sophisticated Cooling, Turbocharger & Charge air

The high output requires an intelligently conceived cooling system. This system is designed to enable the cylinder head and crankcase to be cooled to different temperature levels. This innovative measure allows for a cool cylinder head for maximum output with efficient ignition timing, and a warm crankcase to reduce in-engine friction. Cooling of the cylinder head is ensured by a mechanical water pump, while cooling of the crankcase is via a second, electrically driven high-performance water pump. After a cold start, this pump remains passive until the engine has warmed up. In operation it is regulated by the engine control unit so that the crankcase is always cooled according to the situation.

One Man, One Engine

The new engine is entirely assembled by hand. To this end a completely newly designed production line was constructed in the AMG engine production facility in Affalterbach, where Mercedes-AMG has raised the “One Man, One Engine” principle and Industry 4.0 processes to an innovative level reflecting the latest findings in ergonomics, material flows, quality assurance, sustainability and efficiency. On the road to implementing Industry 4.0, AMG’s hand assembly operation likewise follows the vision of “smart production”. This enables maximum flexibility and is both transparent and highly efficient. It safeguards and improves the quality of the engines and production processes using innovative and digital technologies.

Agile AMG SPEEDSHIFT DCT 8-speed 

The 8-speed AMG SPEEDSHIFT DCT 8-speed dual-clutch transmission also contributes to the GLA 45’s agile and dynamic character. The gear ratios have been configured so that the driver experiences very responsive acceleration in all speed ranges, combined with fast shifting and optimized connections when shifting up. Depending on the selected AMG DYNAMIC SELECT driving mode, the driver receives a specific drive configuration with different accelerator and gearshift characteristics.

The standard RACE-START function allows for maximum acceleration from a standstill, resulting in an exciting display of performance. This also applies to the drive sound with partial ignition interruption when changing up a gear, as well as the automatic double-declutching function when changing down. Despite these performance features, efficiency-enhancing features are also present in the GLA 45: in “Comfort” mode the ECO start/stop function is active; while the “gliding” function can be selected in the “Individual” driving mode.

AMG 4MATIC + all-wheel drive + AMG TORQUE CONTROL

The highly dynamic driving experience is greatly assisted by the standard fully variable all-wheel drive. The secret is AMG TORQUE CONTROL in the new rear axle differential: this includes two electronically controlled multi-disc clutches, each of which is connected to a rear axle drive shaft. In this way, the power can not only be variably distributed between the front and rear wheels, but also selectively between the left and right rear wheel. The result is consistently optimized traction, even in adverse road conditions or during extreme cornering, for example, on a closed race circuit.

Highly-responsive Electromechanical Control

Control of the drive torque to the front and rear axle, and between the two rear wheels, is electromechanical. The influencing factors for torque distribution include not only the driving speed, the lateral and longitudinal acceleration and the steering angle, but also the difference in rotational speed between the individual wheels, the gear selection and accelerator position. The main advantages of electromechanical control over an electrohydraulic system relates to more refined driving dynamics – primarily due to the significantly faster response and speed-independent actuation of the discs over the entire adjustment range.

The characteristics of the all-wheel drive control are dependent upon the drive mode and the AMG DYNAMICS setting. In “Basic” and “Advanced”, the 4MATIC system is in “Comfort” mode. In “Pro” and “Master” (included in the optional AMG DYNAMIC PLUS package) the 4MATIC system switches to “Sport” mode, for even more agile handling and an even higher threshold for the critical limits.

Optimized Suspension Components for Highly Dynamic Handling

The new AMG suspension provides the basis for high directional stability and highly dynamic cornering characteristics with low body roll. At the same time, comfort has been improved compared with the previous GLA 45. The longitudinal and transverse dynamics are ideally coordinated. All suspension components have been thoroughly revised in order to achieve a higher maximum lateral acceleration together with easy vehicle control at the limits.

A McPherson strut design is used at the front axle. The suspension includes one transverse control arm below the wheel center, one suspension strut and one tie rod respectively. The special axle geometry reduces torque steer for exceptional comfort and agile handling. The new aluminum wishbone reduces the unsprung mass and enables a more sensitive response from the springs. The brake calipers at the front axle are radially bolted – a technology from motorsport that brings added stability. The front axle carrier is rigidly attached and thus additionally stiffens the front section.

The 4-link rear suspension is also rigidly connected to the body via a rear axle carrier, and therefore very torsionally rigid. There are three transverse control arms and one trailing arm plus specific bearings per rear wheel. This design ensures maximum driving stability and agility.

‘2021 GLA 45 Sports Brawnier Exterior, Packs More Power’ continued…