Porsche R&D executive explains hybrid vehicle development path

    Porsche, a premium sports car manufacturer, has launched the small SUV "Macan". The company has taken advantage of its position as a subsidiary of the Volkswagen Group and adopted the chassis of the SUV "Q5" of Audi, a premium car manufacturer of the group, benefiting greatly from the modular strategy promoted by the Volkswagen Group.

    Porsche positions plug-in hybrid vehicles (PHVs) as a core technology to improve the environmental performance of sports cars, while Tesla Motors develops pure electric sports cars for the wealthy, forming a sharp contrast between the two positionings.

    The reporter interviewed Wolfgang Hatz (hereinafter referred to as Hatz), the director in charge of R&D at Porsche and previously in charge of the development of traditional power systems (including drive systems such as engines and transmissions) at the Volkswagen Group, about the reasons why Porsche focuses on modularization and PHV development.

——Please explain why Porsche is now launching the small SUV "Macan" on the market.

    Hatz : About three years ago, we discussed the form of cars that Porsche customers would want in the future. That was in 2010, one year after the launch of the premium sports sedan "Panamera". In addition, the SUV "Cayenne" had been a huge success, so we concluded that customers would want a small SUV.

    On the other hand, as a brand under the Volkswagen Group, we have a good technical foundation. That is Audi's "Q5". We thought that if Porsche developed a small SUV based on the Q5, we could create a sports SUV that matches Porsche's values, so we decided to develop the "Macan".

    Although it is an SUV, the Macan achieves driving performance close to that of a sports car. We firmly believe that this car will contribute to Porsche's greater success.

——Macan is part of Volkswagen Group’s shared chassis strategy.

    Hatz: We have a history of chassis sharing, since the Cayenne was based on the Volkswagen "Touareg". Just as with the Cayenne, the Macan has been modified in many ways based on the Q5 to create a completely different car.

    For example, the powertrain (the drive system consisting of the engine and transmission, etc.) was significantly changed. Not only was it equipped with a newly developed V-6 engine, but the transmission, brakes, suspension, and steering wheel were also Porsche-style. Although the wheelbase (the distance between the front and rear wheels) was the same as the Q5, the driving performance was completely different.

- That is to say, in the chassis using Volkswagen's "MQB" module, the parts commonality rate is as high as 70%, but when the Macan and Q5 share the chassis, the parts commonality rate is not that high?

    Hatz : That's right. There are many improvements to the Macan.

    All parts not related to styling and driving performance are shared with Audi

——So, how does Porsche participate in the modular strategy promoted by the Volkswagen Group? Hatz: We have a very clear idea. In terms of differentiation from other cars, Porsche attaches the most importance to styling design. The second is driving performance.

    Less important is the electrical system. Even if the same electronic control unit (ECU) as Audi is used, who would care? For example, the "Macan" uses a touch screen interface developed by Porsche itself, but the electrical system architecture inside it uses the module "MLB" developed by Audi. Therefore, many ECU components are shared with Audi.

——Porsche is responsible for developing the "MSB" module for sports cars, right?

    Hatz: MSB is a standard module for rear-wheel drive or 4-wheel drive, and will be adopted first in the new generation of Panamera. Panamera has just been comprehensively improved in 2013, so the new generation of Panamera using MSB will not be available until a few years later.

    From the perspective of architecture, many parts of MSB are of low importance and are common to Audi's MLB. The electrical system is a typical example. For the current Panamera, even parts developed by Porsche can be shared with Audi to gain scale advantages. This is true for Porsche, and for the entire Volkswagen Group, it also has the benefit of further increasing production.

——What is the biggest benefit of modularization in automotive development?

    Hatz : I used to be in charge of the powertrain development of the entire Volkswagen Group, and was involved in the development of MLB and MQB in terms of powertrain.

    The biggest benefit of modularization is very simple. The architecture directly defines where the engine and transmission are located, so it is relatively easy to develop a variety of models. When developing the first prototype, you only need to install the powertrain according to the design drawings to achieve the driving performance of the car. Because the basic architecture is the same, it is very simple to develop the car. This is because the same exhaust system and catalyst system can be used. Since you don't have to develop all the parts from scratch, you can create many different models with little effort.

    What we (Volkswagen Group) are trying to do today is to standardize the modules. We will standardize the processes in Germany, the United States, Asia, and other parts of the world so that we can build cars anywhere in the world.

    Porsche, as a high-end car manufacturer, has been manufacturing cars in Germany, and the production processes of various factories are basically the same. Now, as long as a car breaks down, the relevant news will spread all over the world in an instant, causing serious problems. Therefore, it is also important to promote standardization based on modularization to improve product quality.

——Porsche is also currently working on the development of PHVs (plug-in hybrid vehicles). As a sports car manufacturer, what blueprint has it drawn up for "automotive electronics"?

    Hatz : In the past, Porsche focused exclusively on petrol engines. It is undoubtedly true that this was successful. But in the future this alone will not be enough.

    In 2009, Porsche introduced the diesel engine for the first time in the Cayenne, which was a great success in Europe. Then, in 2010, the Cayenne launched a hybrid vehicle (HV), and in 2011, the Panamera launched a hybrid. Now, we firmly believe that hybrid vehicles are a very suitable technology for Porsche. Moreover, we believe that the future technology trend will also tend to plug-in hybrid vehicles. Therefore, we decided to step up the reinforcement of plug-in hybrid vehicles at the end of 2010, and launched the Panamera plug-in hybrid in the summer of 2013.

    Plug-in hybrids are positioned as an important technology that will support the next 10 to 15 years, not the next five years. This is because plug-in hybrids can not only drive on the streets with zero emissions, but also support long-distance driving with internal combustion engines. If plug-in hybrid technology is used, it will be possible to provide customers with a dual choice (pure electric vehicles and internal combustion engines) in the medium and long term.

Sports performance is superior to Toyota HV

——When it comes to HVs, Japan's Toyota is at the forefront, while Volkswagen Group, led by Porsche, and other European automakers use different technologies from Toyota. Why is that?

    Hatz : I started to participate in HV development more than 10 years ago. At that time, I was still at Audi. At that time, I thoroughly examined what kind of technical concept was suitable for us, how much power was needed, and other technical feasibility. Of course, it also included Toyota's method of using ECVT (electronically controlled continuously variable transmission).

    After investigation, I think the current mainstream system in Europe, the "P2" system, has more advantages. One of its major advantages is the sporty performance that is crucial to Porsche. CVT (Continuously Variable Transmission) technology also lacks a sporty feel in general driving. Porsche hopes to provide the same feeling as a traditional sports car when starting the engine.

    Of course, the P2 system also has its challenges. That is, can it achieve the same comfort as Toyota's method when switching from the motor to the engine? From the perspective of space, it is not easy to set up a motor between the engine and the transmission. In addition, a clutch is required, making it difficult to develop software that achieves comfort.

    On the other hand, the P2 system has a lot of freedom in choosing the engine and transmission. Because of this great freedom, it can achieve the same engine speed increase method and sound effect as a traditional sports car.

    We decided to use the P2 system for HV 10 years ago. We also applied this technology to PHV. Recently, I found that many car companies are moving in the direction we are moving.

——Isn't Porsche developing an EV? Tesla Motors is said to be developing a sports car EV in the United States, and it has gained great popularity in the field of high-end sports cars...

    Hatz : Porsche believes that the biggest problem is the short driving range of EVs. Also, for sports cars, the heavy batteries are a big issue. However, if the batteries are reduced, the driving range will be reduced rapidly.

    PHVs do not have this problem. Porsche's PHVs can now travel 36km (in EV mode) and will strive to reach 50km in the future. If this driving distance can be achieved, it can be driven as an EV in most situations on the street. If you want to travel long distances or go off-road, you can start the engine.

    When the time comes that a lighter battery is enough to ensure a long driving distance, Porsche may also develop EVs. Because from a technical point of view, EVs have a big advantage, which is that they are much simpler than internal combustion engines. However, there is a bigger problem at present. On the west coast of the United States, EVs are still relatively unpopular, and PHVs are currently the best solution.