The automotive industry continues to be beset with challenges from various aspects, including environmental regulations, fuel efficiency, value enrichment and also innovation. The automobile manufacturers, who vehemently field latest models and variants, are slow to launch new engines. They use a proven engine not only for passenger cars but also for utility vehicles. Developments in engines are not matching those in vehicle models. This is because any new engine has to be innovative, lighter, smarter and more efficient. It is not an easy task. Innovation is the real challenge. Still there have been a few new engine launches by the leading vehicle manufacturers like Toyota, Daimler, BMW and others. This article is a close look at some of them.
Right from the day the Internal Combustion (IC) engine was developed about one and a half centuries ago, there has been continuous efforts to make it more powerful and efficient. The first 50 years of development was primarily on the lines of improving the power. Efficiency was not on the radar; may be due to cheaper fuel prices. The following five decades witnessed works to make engines more efficient in terms of optimising power to weight ratio etc. During the last 50 years the focus was on improving the engines’ fuel efficiency and this became dominant after the oil shock of 1973. The second half of this period saw engines being developed with a combination of features like fuel efficiency, light weight and eco-friendliness. Now the engine designs blend high-end performance with advanced technologies that reduce emissions while substantially improving fuel economy.
Off late engines with smaller displacements and less cylinders (preferably three) have become very popular; this is despite keeping the myth that engines with three cylinders cannot be efficient. Nevertheless, forced induction motors dominate modern engines; the naturally aspirated engines also witness several improvements.
Toyota has recently introduced a new engine, the 2.8-litre D-4D turbo-diesel motor, which is likely to make its UK debut in Land Cruiser soon. The engine represents the first fruits of advanced new design and technology to achieve much higher fuel efficiency, lower emissions and quieter operation. The engine (1GD-FTV) is the first in the world to benefit from ‘Thermo Swing Wall Insulation Technology,’ making it one of the most thermally efficient in the market with a rating of 44 percent.
Although it is smaller than the 3.0-litre engine it is replacing, it offers 25 percent more torque. Usefully, there is 11 percent more torque available at low revolutions, and enhances the fuel economy improvement by 15 percent.
In testing, the new engines have proven their high thermal efficiency, quiet operation and powerful performance in worldwide locations, including extremely cold environments, where temperatures can fall to -40°C, and at high altitudes above 4,500 metres.
Toyota has also been able to make the engine catalyst 30 percent smaller. It has reduced the number of exhaust layouts from 18 to just three, simplifying the engines’ deployment worldwide and reducing the environmental burden.
Key to the performance of the new engines is the world-first application of Thermo Swing Wall Insulation Technology, together with a SiRPA (a silica-reinforced porous, anodised aluminium coating) on the pistons, reducing the cooling loss during combustion by about 30 percent. SiRPA’s high insulation and dissipation qualities make it easy to heat and to cool.
The air intake port has been shaped to allow a significant increase in the amount of airflow into the cylinders; the piston combustion chamber shape has been revised; and the common rail fuel injection system allows for more advanced pressure control and injection optimisation. Air consumption is maximised, which enables high thermal efficiency and low emissions to be achieved.
The GD engines use a new turbocharger that is 30 percent smaller than its predecessor. Produced in-house by Toyota, it has a new turbine that improves efficiency and a new impeller that gives instantaneous throttle response and allows maximum torque to be obtained over wide engine rev range. The high-dispersion urea selective catalyst reduction system eliminates up to 99 percent of NOx emissions, one of the principal causes of air pollution. This helps the engine conform to Euro 6 and other international emissions standards.
Toyota plans to replace the KD family of engines with the new GD units. By 2016, production will reach about 700,000 units a year. They will be available in around 90 world markets.
Similarly, several OEMs have developed new engines in the recent past. All of them have not been successful in the world market. Therefore, the International Engine of the Year Awards, presented by the Engine Technology International magazine are considered important by the engine makers. They are selected by 65 motoring journalists from 31 countries.
Since 1999 these awards have grown in stature, with car makers from around the world competing fiercely to make it to the top slot. Over the past few years, the awards have become an important marketing tool for the winning OEMs. They prominently display the awards’ logo in their media campaigns.
This year, the choice was on powertrains that made inroads into weight reduction. Reflecting the rise of powertrain electrification globally, there were more all-electric and plug-in hybrid products for judges to assess than ever before. The key innovations came from BMW, Kia, VW, Audi, Mercedes-Benz and BYD.
One of the most crucial categories is the ‘New Engine’ award, representing the greatest development of the past 12 months; this year there were three absolutely scintillating creations that went head to head: the progressive PHEV powertrain in BMW i8; the screaming 4-litre bi-turbo in Mercedes-AMG GT; and the heart-thumping charged V8 power plant in Ferrari California T.
BMW Bags Four
This year BMW Group won four awards demonstrating the OEM’s engine-building prowess. The drive unit in the BMW i8 earned two wins. It was declared the overall winner. The BMW i8 unit was voted winner for its TwinPower Turbo three-cylinder petrol engine. Its overall drive unit won the best ‘New Engine’ award. The combination of electric motor and petrol engine earned the overall victory for BMWi8.
In the 2.5 to 3.0-litre displacement category, the M TwinPower Turbo six-cylinder in-line petrol engine of the BMW M3 and BMW M4 also came on top.
This fourfold success for the BMW Group vindicated the performance potential of its ‘efficient dynamics’ technology package. Since 2007 it has enabled the company to offer driving pleasure while cutting fuel consumption and emissions.
The three-cylinder engine in the BMW i8 develops 170 kW/231 hp and drives the rear wheels. The 96 kW/131 hp electric motor draws its energy from a lithium-ion battery (charged from a conventional domestic power socket) and sends its power to the front axle. This bespoke plug-in hybrid system, developed and produced by the BMW Group, enables a range of up to 37 kilometres in the EU test cycle and a top speed of 120 km/h on electric power alone. This gives a ‘glued-to-the-road’ all-wheel driving experience headlined by powerful acceleration and a dynamically-biased distribution of power through keenly taken corners.
The more powerful of the two sources drives the rear wheels and uses the electric boost from the hybrid system to augment driving comfort while offering higher levels of efficiency. The sprint from 0 to 100 km/h takes just 4.4 seconds. The combined fuel consumption – as calculated in the EU test cycle for plug-in hybrid vehicles – stands at 2.1 litres per 100 kilometres plus 11.9 kWh of electricity. This equates to CO2 emissions of 49 grams per kilometre. This correspondent experienced the technological prowess of the vehicle recently at Contidrom in Hannover.
On the challenges in developing the award winning engines, the Spokesperson of BMW group said, the biggest one was the combination of a combustion engine with an electric engine. “The engines have to work together perfectly under every condition. In the case of a plug-in-hybrid sports car like the BMW i8, it is very important that the activation and deactivation of the engines happens so smoothly that the driver can´t feel any sudden movement of dynamic impulse,” the spokesperson said.
On the prospects to further up the efficiency mark, the Spokesperson said, “The whole power train of the BMW i8 is already very efficient. The fuel consumption is already as low as 2.1 l/100km (EU cycle). We are always searching for ways to improve the fuel consumption of our engines and drive trains.”
The M TwinPower Turbo six-in-line petrol engine has a high-revving for a turbocharged engine, resulting in linear power delivery over a wide engine speed range. The technology ensures that peak torque is on tap over a broad rpm range. Yet another attribute is its outstanding efficiency.
Mercedes‑AMG has taken a title with its 2-litre four-cylinder turbo engine. In the ‘1.8-litre to 2-litre’ category, the high-performance engine was able to triumph over its top-level competitors. With another win in the 1.8-litre to 2-litre power category, the company has once again demonstrated its expertise in the development and production of high-performance engines which do justice to the motorsport genes of the brand.
Ralph Illenberger, Head of Engine Development, (4-/ 6-/ 12-cylinders), Mercedes-AMG, told AutoParts Asia that the main innovation challenge was to optimise the overall performance of the engine, and its drivability. Therefore the focus was on optimising the complete combustion process and developing a highly efficient engine.
The engine once again proves that performance does not come at the cost of environmental compatibility. For instance, the GLA 45 AMG also holds the pole position with regard to driving dynamics: it accelerates from zero to 100 km/h in 4.8 seconds and reaches a top speed of 250 km/h (electronically limited).
Illenberger said that, “One of the key factors is to optimise the cooling concept for such high power outputs. A lot of development work had been on this challenge. Thanks to the charging system with a tubular manifold and a twin scroll turbo charger, the engine offers good drivability and maximum performance”.
“The setup of the development from the AMG M133 was focused on virtual development. The targets were to get the most efficient and powerful 2.0 litre 4-cylinder engine. Therefore, we did detailed CAD studies with all necessary simulation at the beginning, a complete digital build phase. This enabled us to simulate several concepts – the current engine concept was by far the most convincing one,” he said.
Right from the start the focus was on better fuel efficiency and power output. “Therefore, we reduced the friction, improved the charging system and the combustion process,” Illenberger said.
The M838T engine from McLaren Automotive has retained the prestigious ‘3-litre to 4-litre’ title at the 2015 edition. This achievement marks a third successive victory for the highly-efficient twin turbo engine fitted to the core models in the McLaren Super Series, the 650S Coupé and 650S Spider.
The 3.8-litre twin turbo V8 petrol engine has been designed and developed by the British manufacturer of luxury, high-performance sports cars. McLaren in collaboration with Ricardo has made significant changes to the introduction of the McLaren 650S in 2014. Producing, as the name suggests, 650PS (641bhp) and 678Nm (500lb ft) of torque, the engine accelerates from 0 to 100 km/h in 3.0 seconds, but is as focused on efficiency as it is on power. The 650S returns 11.7 litre /100km on the EU combined cycle, emissions of just 275g/km; interestingly it is exempt from gas guzzler tax in North America. The M838T engine in the 650S Coupé and Spider is exclusively filled with Mobil 1 New Life 0W-40. The high technology engine lubricant has an optimum combination of synthetic base oils designed to meet the high performance engine demands.
Richard Farquhar, Head of Powertrain, McLaren Automotive said, “The M838T is a wonderful piece of powertrain engineering and has enjoyed tremendous success from the outset. The 3-litre to 4-litre category continues to be extremely competitive, so claiming victory for the third year running confirms that the engine’s ferocity, responsiveness and excellent efficiency remain a benchmark in the industry.”
The McLaren M838T is assembled at a state-of-the-art engine production facility at Ricardo’s Shoreham Technical Centre. The facility provides a near clean-room production environment in which every process is carried out according to strict, best-in-class quality principles and within a comprehensive ‘no faults forward’ culture. Due to the success of the collaboration on the V8 engine, this facility is being expanded to allow assembly of up to 5,000 engines a year, said Ricardo director of McLaren programmes, Jason March.
“We are proud to have helped McLaren in designing and developing this triple award-winning engine, and also in assembling it at our high performance assembly facility,” March said.
The Audi 2.5-litre TFSI engine won the award in the 2 to 2.5-litre category. The five-cylinder engine has now won the award for the sixth consecutive time. The jury gave these reasons for its decision: “Reliable Audi quality and excellent tuning make this engine a genuine pleasure to drive. No synthetically designed sound could replace the passionate sound of this magnificent in-line five-cylinder engine.”
Board Member for Technical Development, Prof Dr Ulrich Hackenberg said, the five-cylinder engines have a long tradition at the company and it made Audi a sporty brand back in the 1980s. The 2.5 TFSI in the new Audi RS 3 Sportback is significant for its immense torque, voracious revving abilities and a unique sound.
The direct-injection and turbocharged 2.5 TFSI engine produces 270 kW and makes the RS 3 Sportback the most powerful car in the premium compact class. Its peak torque of 465 Nm is already available at 1,625 rpm and remains constant up to 5,550 rpm. The car accelerates from 0 to 100 km/h in 4.3 seconds and can reach a top speed of 280 km/h.
The Spokesperson of Audi, Graeme Lisle, told this correspondent that the challenge was to build the most powerful five-cylinder car in RS history for the new Audi RS 3 Sportback. “This target was achieved as the 2.5 TFSI five cylinder engine in the new Audi RS 3 Sportback produces 367 horsepower. We have also been able to increase the maximum speed 280 kph, which is 30 kph more than its predecessor. That is a unique number in the segment.”
This is the eleventh time that an engine from Audi has been voted for this award. Between 2005 and 2009, the company won the coveted honour five consecutive times with the 2.0 TFSI in the 1.8 to 2.0-litre category. This represents the sixth victory in a row for the 2.5 litre TFSI.
On the prospects of raising the efficiency curve, Lisle said, “a big achievement for us over the last year was that the 2.5 TFSI engine not only achieves 367 horsepower but also the EU6 emission standard. In the new Audi RS 3 Sportback we were able to reduce fuel consumption by 10 percent compared to its predecessor – this high performance car now consumes 8.1l/100 km. Our strategy is to continue to develop the five-cylinder engine,” Lisle said.
Ford’s 1.0-litre EcoBoost engine is adjudged the best engine under 1.0-litre for the fourth consecutive year. It is the only engine ever to be named overall winner three times in a row and chosen for attributes like drivability, performance, economy, refinement and technology. Ford is exploring new cylinder-deactivation tech for further efficiencies.
Ten models in Europe can be equipped with the 1.0-litre EcoBoost engine. One in five all-new Ford vehicles sold in Europe in 2014 was equipped with the 1.0-litre unit, including almost two in five for Fiesta.
“The 1.0-litre EcoBoost engine changed the game for small petrol engines and we are proud it remains best in class despite a growing number of competitors,” said Joe Bakaj, Vice President, Product Development, Ford of Europe. “The spirit of innovation that helped us create this engine is alive and we continue to develop new engines.”
Ford is working with engineering partners at the Schaeffler Group to test a new dual mass flywheel that enables cylinder deactivation to take place at a wider range of engine loads and speeds, and to enhance refinement. On-road tests using a working prototype at the European Research and Innovation Centre in Aachen, Germany, showed fuel efficiency improvements of up to six percent.
“Even for an aggressively downsized engine such as the 1.0-litre EcoBoost, a significant improvement in vehicle fuel economy could be found by exploiting cylinder deactivation,” Carsten Weber, advanced powertrain manager, Ford of Europe, said. “The highest priority in the development of new combustion engines for automotive applications is the ongoing reduction of fuel consumption.”
Available with 100 PS, 125 PS and 140 PS, the 1.0-litre EcoBoost engine powers vehicles in 72 countries worldwide. Globally, Ford’s range of powerful yet fuel-efficient EcoBoost engines includes 1.5-litre, 1.6‑litre, 2.0-litre and 2.3-litre four-cylinder engines, and 2.7-litre and 3.5-litre V6 engines. The latter is being developed to power the all-new Ford GT supercar that will see the company return to racing in Le Mans in 2016.
For the fifth year running a Ferrari engine has triumphed in two categories of the awards – Performance Engine of the Year and in the above 4-litre class. This is the naturally-aspirated 4.5-litre V8 engine which, in its most powerful guise, equips the 458 Speciale and Speciale A.
The V8 won both the awards two years running in 2011 and 2012. That success was repeated in 2014 and now again in 2015. Its unmatched run of victories has only been interrupted by the naturally-aspirated, 740-hp 6262cc V12 equipping the critically acclaimed Ferrari F12berlietta, which took the same accolades in 2013 with the V8 in second place.
Ferrari’s Powertrain Department Head, Vittorio Dini said, “For our team, winning both these titles for the fourth time is a crowning achievement that testifies to the world-class performance of our naturally-aspirated V8 engine family.”
Ferrari’s V8 reached the pinnacle of development in the 458 Speciale and the limited-series edition Speciale A, where the naturally-aspirated 4.5 litre produces 605 hp at 9000 rpm.
PSA Peugeot Citroën
PSA Peugeot Citroën received the coveted award for its 3-cylinder Turbo PureTech engine in the 1.0-litre to 1.4-litre category, crowning a successful run that has already seen 100,000 units roll off the production line at the Française de Mécanique plant in Douvrin, France.
The PureTech family of 3-cylinder engines boasts of high levels of performance, cutting fuel consumption and CO2 emissions by an average of 18 percent compared with its predecessors. The 1.0-litre and 1.2-litre naturally aspirated versions were being manufactured since 2012 at the French Trémery plant, which has an annual production capacity of 640,000 units. The 1.2-litre turbo versions were split since 2014 between the Française de Mécanique plant and the Xiangyang plant in China, which have respective annual production capacities of 320,000 and 200,000 units.
It may be recalled that in March 2015 at an event attended by French President François Hollande, PSA Peugeot Citroën announced that it would increase the Trémery plant’s production capacity by 200,000 units. The announcement followed a surge in demand for the Turbo PureTech engine, which equips the car manufacturer’s mid-range models.
The PureTech family of engines is fitted on several of the Peugeot, Citroën and the Dongfeng Peugeot models. Christian Chapelle, Vice President Powertrain and Chassis Engineering, PSA Peugeot Citroen said, “With overall average emissions of 110.3 grams per kilometre, PSA leads the European market on the CO2 front. This prestigious prize for our 3-cylinder Turbo PureTech engine rewards the Group’s engineering expertise in petrol engines. It is wonderful recognition of the technological progress we’ve made through R&D as part of our ongoing drive to lower fuel consumption.”
In order to sustain a global gasoline engine strategy and to have the most efficient gasoline engines, PSA Peugeot Citroën has totally renewed its gasoline portfolio. The PureTech targets were CO2 efficiency, to offer mainstream gasoline cars emitting around 100 g/km of CO2; and fun to drive, to meet the ambition of moving upmarket thanks to the turbo derivatives.
Denis Fourchon, 3 cylinders Petrol Engine Family EB Pure Tech Chief Engineer, PSA Peugeot Citroen, told AutoParts Asia that from a technical point of view, the PureTech targets were compact package-weight, to be installed in all B and C range, modularity to optimise cost and the time to market and to achieve the highest quality standards. Besides, investments and production, the PureTech process has been designed according to the (Lean Manufacturing Engineering) principles.
“Considering the 96 kW performance target and the customer demand for mid-size class vehicles attributes, the engine displacement of 1.2 liter has been identified as the right scaling and the most optimised efficiency balance between downsizing effect and efficiency. In order to decrease fuel consumption while maintaining good drivability, we set high downsizing targets on specific torque and power. With 192 Nm/l specific torque, the PureTech 130 engine is at benchmark level for passenger mainstream car. These targets lead to high mechanical and combustion constraints. To achieve these levels, major improvements have been made on base engine, efficiency and NVH.”
On the opportunities to tweak the engine further, Fourchon said, the studies for the next engine generation were on variable compression ratio, cylinder deactivation, coasting, miller cycle and also kaizen improvements on combustion and friction. And to make a big step forward in fuel consumption, it will be necessary to introduce new hybrid powertrain and to increase its market share by decreasing the overall cost of this technology, he said.
The components manufactures play a vital role in the success of any vehicle; the onus of the OEMs is narrowing down to design, integration and manufacturing, while the suppliers are graduating from catering to mere components to systems and modules. The support of suppliers has been increasing as many global players in this arena offer the vehicle makers solutions to address the market requirements such as enhancing efficiency, containing emissions and becoming lighter.
Audi’s Lisle says yet another challenge was to reliably transmit up to 465 Nm of torque from the 2.5 TFSI engine to the wheels. “Many components in the drivetrain of the Audi RS 3 Sportback had to be strengthened for this to be achieved. The entire tyre range was also specially developed for the new RS 3 Sportback. As a result, the driver can feel safe even at the highest speeds.”
According to BMW Group Spokesperson, what really makes the BMW TwinPower Turbo 3-cylinder petrol engine so powerful and efficient is the combination of fully variable control of intake valve lift (VALVETRONIC), the continuously adjustable camshaft timing for the intake and exhaust valves (Double-Vanos) and the turbocharger that is used for ideal gas-exchange cycle characteristics in order to achieve fast pressure build-up, spontaneous response and free-revving performance.
Illenberger adds, “The first time we had the challenge to develop a series engine with a power output from 133KW/l; therefore, we had to develop a crank housing and cylinder head with our Mercedes colleagues for a peak pressure from 140bar. So we worked together closely with our colleagues from the casting production in-house. The other challenges were the manifold and the twin scroll turbo charger, a topic we handled thanks to a very good relationship with our suppliers.”
According to Fourchon, for each subsystem and components challenging requirements have been set to ensure that the engine will be state-of-the-art when it will arrive in mass production. To reach the best trade-off between attributes while preserving an optimised cost and a high level of components and industrial commonality with the naturally aspirated versions, a successful co-development work has been achieved with the suppliers. “A close work on product and process design with the suppliers in order to push innovation and technologies improvements is a key factor for the success of the development. For the Puretech Turbocharger version, the main key contributors have been Valeo for the software and control unit, Valeo/Delphi for the fuel system, Honeywell for the turbocharger, MIBA for the balancershaft, Malhe for MAP-regulated oil pump,” he said.
Though new engine development and enhancing the efficiencies of the existing engine platforms have been a continuous process, the new challenges pose a threat to further improvements. While on the one had the vehicle needs to be fuel efficient, the regulations drive the developers to make it environment- friendly. On top of it the fossil fuel availability threat presses hard the development on making the fuel guzzlers to fuel sippers. All these factors that challenge innovation continue.