Some engineers and experts across the automotive industry believe the best way to reduce emissions and improve the fuel efficiency of vehicles is to develop a number of different technologies within the powertrain that work in unison. Consequently, developments in a large variety of different components, from roller bearings to batteries, have been continuously updated in the hope of achieving a cleaner and more efficient vehicle. Here, Megatrends examines the potential for combining products to build a better powertrain.
Gasoline Technology Car
Continental and Schaeffler recently developed a concept car that utilises a variety of technologies and components to reduce emissions and increase the efficiency of the powertrain. The Gasoline Technology Car (GTC), which was first presented during the International Vienna Motor Symposium in May 2014, has several unique characteristics as a hybrid vehicle. Since the Motor Symposium, the companies have been busy polishing and tweaking the vehicle, optimising the technologies in order to obtain the best results before the technology enters production.
The GTC is similar to other hybrid cars, in that there are two sources of power that work to instigate propulsion – a battery and the burning of gasoline. It uses as a platform the Ford Focus, a car which can be ordered with an efficient, 1.0-litre EcoBoost downsized and turbocharged three-cylinder engine. By using the downsizing and turbocharging processes, manufacturers are able to reduce the weight and increase the efficiency of the powertrain whilst maintaining original levels of performance and power. Yet, the GTC also uses a number of technologies and components that are not normally found in many hybrid vehicles.
What’s the difference?
Although the GTC holds characteristics similar to that of other hybrids, there are certain differences that set the car apart from its competitors. Thomas Knorr, Project Manager for Technology & Innovation, Powertrain Division at Continental, explained to Megatrends the various technologies implemented within the GTC, including Continental’s 48-Volt Eco Drive System. “By using a 48 Volt system, we don’t have the disadvantages like expensive insulation and protection measures against the high voltages,” he told Megatrends. The companies have recorded a reduction in CO2 emissions, down from the 114 grams that was originally achieved in the Ford Focus, to 95 grams – an overall decrease of around 17%. The 48-Volt Eco Drive System accounts for most of the fuel savings and emission improvements, although there are a number of other technologies that help it do so.
Among the notable features of the GTC is Schaeffler’s electronic clutch. Markus Kneissler, Head of Development, Automated Clutches at Schaeffler, described how the innovative clutch works. “As soon as the drivers’ foot leaves the gas pedal, the clutch disengages the engine from the drivetrain. Up to now, only automatic gearboxes could do so,” stated Kneissler. The electronic clutch works to make the engine disconnect feature smooth and responsive, without the “delay in torque” that often came with previous drivetrain disconnecting systems.
Once the engine has been disengaged and the vehicle continues to move, it enters coasting mode as the clutch allows it to maintain kinetic energy. “You can release the gas pedal, and then the engine is switched off and you enter coasting mode. If you press the gas pedal again, the engine is switched on, the clutch is closed again and you can accelerate nearly immediately,” explained Knorr. The GTC uses no fuel during coasting mode, which can be particularly valuable when travelling long distances whilst maintaining a consistent speed. Knorr is confident that during an average journey. Drivers could use the coasting mode for as much as 25% of the time. Therefore, the coasting feature could secure significant savings in fuel. Yet these potential savings cannot be specified in drive-cycle tests as they will vary with each journey taken.
Some of the energy saved during coasting mode is fed to power other features of the vehicle, such as the electrically heatable catalytic converter. Whilst the engine is off, stops burning fuel and goes cold, the catalytic converter stores energy that can quickly heat up the engine, reducing friction losses by up to 10%.
What are the drawbacks?
One of the main drawbacks of having so many technologies implemented in one vehicle is an increase in weight. Due to the various technologies that are implemented in the car, specifically electronic features, the savings in weight that would otherwise be available thanks to the small battery are lost. However, Knorr explained that “since the vehicle is only a few kilograms heavier, the fuel-saving features more than make up for it.” This weight disadvantage will have a negative effect on the figures obtained during drive-cycle tests, he admitted, suggesting they are likely to differ to real-world figures. “We should find differences to that NEDC,” he said.
The GTC still has a significant journey ahead of it before its technology can be brought to mass commercialisation. “As the automation of the vehicle has just been finished, we have not driven it in real-world traffic,” said Knorr. “The 17% fuel saving may be different in real-world conditions, but with the help of coasting and other features, we are confident of a minimum of 20% fuel saving,” he added.
Vishal Sapru, Research Manager and Growth Consultant, Energy and Power Systems at Frost and Sullivan believes that many OEMs will not invest in a product before it has extensively proved itself through tests – both drive-cycle and real-world – and is certain to have financial benefits for them. With this uncertainty surrounding the figures of fuel saving, OEMs may be reluctant to invest in the GTC.
A joint force
Continental and Schaeffler are also confident that existing production lines for conventional cars do not need to be modified extensively to allow for the production of cars using the GTC’s technology. “Batteries are normally the biggest cost involved in hybrids,” said Knorr. “But not here. It a small 48 Volt battery, and should be easy to install in cars, as well as fit into production lines.” What is more, OEMs are able to choose what GTC technologies and features they use by working with the suppliers. A unique flexibility comes into play here, not just in terms of how efficient the vehicles can be, but how much they will cost. Sapru believes that like consumers, OEMs enjoy having a choice when it comes to implementing new technologies in their cars, as they are able to control how much they spend on producing them, as well as how much consumers will pay for them at market.
By working together on the GTC, Continental and Schaeffler have produced a portfolio of technologies that divide the efforts to reduce emissions and improve efficiency. They have described the GTC as a testament to having powertrain components that collectively work towards a shared goal. “One part of the system helps the other,” explained Knorr. He believes that overall, the combination of technologies is beneficial to all aspects of the vehicle. “With the integrative GTC approach, the whole is more than the sum of its parts. The formula 1 + 1 = 3 sums up this effect,” he concluded.