Will the E-axle Become a Miracle of Efficiency?

New Drive Concepts Enable Efficiencies of Well Over 90 Percent

Energy efficiency, range, cost efficiency: development projects in the field of electromobility are always caught between these conflicting priorities. A particular focus in this context is on concepts in the field of electric drive axles. Key figures such as efficiency levels well above 90 percent and consumption below 10 kilowatt hours per 100 kilometers make people sit up and take notice. At the VDI Congress DRITEV 2025 on July 9 and 10, 2025 in Baden-Baden, project manager Dipl.-Ing. Christian Schmidt, AVL List, will speak about a current development project. In our interview, he describes how an internal pre-development project turned into a customized series product and what potential the technology offers.
 

Mr. Schmidt, the newly developed electric drive axle impresses with an efficiency of up to 94 percent according to the CLTC cycle. Was this project intended for series production from the outset?

Christian Schmidt: At AVL, R&D projects often initially serve to demonstrate technological possibilities and support customer acquisition. However, our aim was always to bring the concept, or at least aspects of it, into series production. Originally, we mainly wanted to demonstrate what is technically feasible – but it soon became clear that we had developed a very practical solution that attracted interest from OEMs. In the current configuration of the e-axle for an Asian manufacturer, the basic technical concept has actually been adopted almost unchanged in the customer project. 
 

When did the development process begin and what is the timetable for the future?

Christian Schmidt: The internal project started in August 2023, the customer project around a year and a half later. The project is currently in the confirmation phase for series production; a possible start of series production is realistic for 2027. In the current phase, extensive vehicle tests are being carried out to confirm readiness for series production and make final adjustments.
 

Which specific features ultimately made it into the series?

Christian Schmidt: The structural concept of the axle was largely adopted. We had to slightly adapt the voltage level for the electric motors to the customer's vehicle, it is slightly below 800 volts. The electric motors were also individually optimized, including the gear ratios. The basic winding technology with hairpin design was retained. However, the printed windings from pre-development have now given way to conventional production technologies. The control strategy, in which a second electric motor is only switched on as required, has also been incorporated into series development.
 

What were the reasons that convinced the manufacturer to opt for this solution?

Christian Schmidt: A decisive argument was the exceptional efficiency of 94 percent according to the CLTC cycle, which was also contractually agreed. The customer's goal was also to keep energy consumption below 10 kilowatt hours per 100 kilometers, which is achieved with this drive concept. In addition, our approach of switching on a second machine as required was convincing, as this minimizes losses and allows efficiency peaks to be achieved.
 

How did you achieve these impressive figures?

Christian Schmidt: During the pre-development phase, we automatically calculated thousands of variants and thus selected the optimum combination of electric motor, transmission and operating strategy. Another key factor was the option of only switching on a second electric motor when required to minimize losses. Overall, the concept significantly reduces bearing and transmission losses. We also made detailed optimizations to the topology of the electric motors to further increase electrical efficiency. This combination of technical innovations and optimization ultimately led to these outstanding results.
 

Which vehicle segments particularly benefit from your technology?

Christian Schmidt: The e-axle is particularly suitable for vehicles in the C and D segments, but also when high performance is required for short periods. There are many advantages in the SUV segment and in off-road operation, for example, as more power is often required in certain driving situations, while most of the time you are on the road with less power. Our technology makes it possible to cover both situations efficiently.
 

What about production costs and sustainability?

Christian Schmidt: The admittedly higher material costs of the electric axle can be offset by optimizations elsewhere, for example in the battery size and therefore also in its costs. The lower energy consumption also reduces the vehicle weight. The smaller battery additionally leads to a lower CO₂ footprint during production. We also achieve sustainability through the conscious use of materials that are very easy to recycle.
 

How do you assess the market potential of e-axles in general?

Christian Schmidt: The e-axle has the potential to establish itself in various vehicle classes, particularly through the combination of increased efficiency and cost savings. The market is developing rapidly, and we are seeing great interest in Asia in particular. In the long term, we assume that sales figures for electric vehicles will continue to rise and that vehicles will be equipped with highly integrated, compact drive units.
 

In which fields do you expect the next big technological leaps?

Christian Schmidt: In addition to improvements in winding technologies and higher speeds, I see great potential in integrated solutions in particular, for example through optimized cooling and thermal management concepts. The area of additive manufacturing, particularly in winding design, could also play a major role in the future. We are continuously working on testing and optimizing new manufacturing processes in this area.