Audi has introduced its latest MHEV Plus technology, a cutting-edge 48-volt mild hybrid system that elevates the driving experience in the A5 and Q5 series. This advanced system not only enhances performance on highways but also enables partial electric driving in city traffic. By supporting the internal combustion engine with electric power, it optimizes fuel efficiency while supplying energy to components such as the electric air conditioning system. The 48-volt electrical architecture plays a crucial role in reducing carbon emissions while simultaneously improving both performance and driving comfort.
Built on the Premium Platform Combustion (PPC), the latest A5 and Q5 models mark Audi’s first internal combustion engine vehicles equipped with the MHEV Plus system. This 48-volt mild hybrid technology supports the combustion engine, reduces CO2 emissions, and enhances agility and performance. It features a fully integrable Power Transmission Generator (PTG) that enables seamless transitions between electric and hybrid driving modes. As a result, fuel consumption is significantly lowered, and the driving experience becomes smoother and more refined.
Geoffrey Bouquot, Member of the Board of Management for Technical Development at AUDI AG, emphasized the strategic importance of MHEV Plus, stating, “With the new MHEV Plus technology, we are advancing electrification in our internal combustion engine vehicles built on the Premium Platform Combustion, tailored to meet the evolving needs of our customers.” He further added, “This innovation strengthens our diverse portfolio, which includes fully electric models, plug-in hybrids, and highly efficient internal combustion vehicles.”
MHEV Plus offers a host of advantages, including partial electric driving, enhanced efficiency, power-boosting capabilities, and greater driving comfort. The mild hybrid system in the new Audi A5 and Q5 consists of three core components: an integrated power electronics system, a synchronous motor (PSM), and a compact yet powerful Power Transmission Generator (PTG). These work in perfect harmony with a 48-volt battery to deliver optimal performance.
To ensure maximum efficiency, the 48-volt system features liquid-cooled components that maintain ideal operating conditions. Designed to be seamlessly integrated into various models equipped with front-wheel and quattro drivetrains, the MHEV Plus system enhances both hybrid and fully electric driving experiences. This architecture not only boosts performance and responsiveness but also contributes to lower fuel consumption and reduced CO2 emissions.
For instance, in the A5 2.0 TDI (150 kW quattro) (fuel consumption: 5.7–4.8 l/100 km; CO2 emissions: 150–125 g/km; CO2 class: E–D), the system enables savings of up to 10 g/km CO2 or 0.38 l/100 km. Meanwhile, the 3.0 TFSI V6-powered S5 (270 kW quattro) (fuel consumption: 8.0–7.4 l/100 km; CO2 emissions: 182–169 g/km; CO2 class: G–F) achieves reductions of up to 17 g/km CO2 or 0.74 l/100 km (WLTP).
One of the most notable advantages of the MHEV Plus system is its ability to enhance both driving comfort and vehicle performance. At the heart of this innovation is the Power Transmission Generator (PTG), a compact yet powerful electric drive module that represents a significant leap forward from Audi’s previous MHEV technology, which relied on a belt-driven starter-alternator. The PTG is integrated with power electronics and directly mounted on the transmission output shaft. It contributes up to 18 kW (24 PS) of additional electric power to the drivetrain, offering up to 230 Nm of torque at launch.
Audi has engineered MHEV Plus to meet the evolving demands of modern drivers, incorporating next-generation efficiency-enhancing features. Earlier mild hybrid and start-stop systems focused on regenerative braking, coasting, and fuel-saving stop/start functions using 12V or 48V configurations. However, the new MHEV Plus technology introduces an even higher level of electrification, bringing benefits such as enhanced start-stop comfort, emission-free gliding, electric-only parking and maneuvering, and electric-assisted engine performance.
This system allows the vehicle to drive purely on electric power under specific conditions, keeping the internal combustion engine off for extended periods. For instance, it activates during slow urban commutes, when traffic slows on highways, or while approaching city centers. Additionally, the PTG system enhances initial acceleration by delivering up to 230 Nm of torque at low speeds, ensuring a more responsive and agile driving experience.
With the MHEV Plus system, Audi reaffirms its commitment to pushing the boundaries of hybrid technology, offering a seamless blend of efficiency, performance, and driving pleasure.
