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ENGINE DOWNSIZING

ENGINE DOWNSIZING

Downsizing automotive engine and maximising power output with best of class fuel economy while complying to the upcoming BSVI emission norms will be a game changer for the Indian automotive industry.

From larger perspective, one of the key automotive megatrend is downsizing and lightweighting automobile engines and prime movers, without compromising their performance, fuel economy and emission compliance in any way. Most manufacturers have been working on new design concepts, use of alternate materials and individual engine components to downsize and lightweight the same in order to align the same with the upcoming and many futuristic automobile concepts like connectivity, autonomous driver assistance, semi and fully hybrids, reducing carbon footprint, enhanced safety, comfort
and others.

A major thrust to downsizing automobile engines also came from Formula 1 racing in 2014, wherein they reduced the engine size from V8 to V6 and also capped the investment for developing the new engines. However, owing to sporting reasons, there are possibilities of rolling back this decision in future. In any event, the concept is here to stay.
All auto majors present in India are on track to develop their own versions of downsized engines for their entire product range starting from entry level passenger cars and two wheelers to the largest of trucks and buses manufactured by them. Going forward, this will be a game changer for the entire automotive industry in India.

What is Engine Downsizing?

Downsizing an engine has nothing to do with its performance. Simply, it is a method to reduce its weight to the minimum possible and achieve a best-of-breed power-to-weight ratio and make it more efficient. In India, RTO regulations classify automobile internal combustion engines on the basis of their total air displacement volume per cycle in either cubic centimetres (cc) or litres (Lt) and later by the type of fuel used and other automobile specifications. Hence, to begin with, it is most significant to reduce the air displacement of an engine and the work on other aspects to improve its overall performance. It would be appropriate to mention that an engine is one of the heaviest aggregates of an automobile, especially passenger vehicles.
Improvement of efficiency is more than ever before the focus of current research and development activities, not only in research institutions, but also in industry. Increasing engine efficiency, hence reducing the fuel consumption in addition to reducing the driving resistance, is the only way to reduce the CO2 emissions of cars and other transportation vehicles driven by internal combustion engines. Although the CO2 emissions caused by road traffic are responsible for 20 per cent of the overall CO2 emissions in Germany, a comprehensive reduction of CO2 emissions requires a reduction in all relevant areas. In view of the different fuel qualities, two concepts found their way into modern vehicles for worldwide application. One is the concept of downsizing where high specific power is achieved by boosting. To maximise the driving response, these engines are increasingly equipped with direct fuel injection and homogeneous mixture distribution. The second concept is high efficiency achieved by reducing friction and pumping losses. Direct fuel injection with stratified mixture distribution is one of the single measures offering the highest potential to increase engine efficiency. The combination with turbocharging has even higher potential to further reduce fuel consumption, but has high demands on mixture preparation and in-cylinder flow. This technology is presently the focus of research and development activities. Future concepts to increase engine efficiency will combine different technologies such as direct fuel injection, boosting and variable valve actuation. The spark-ignition (SI) engine with direct injection (DISI) represents a combination of the combustion phenomena of both SI (Otto) and compression ignition (diesel) engines and should, in principle, be able to combine the advantages of both engine concepts. In particular, at part load operating conditions, unthrottled operation with stratified charge and a lean mixture offers similar fuel economy to that of compression ignition engines. The improvement in fuel consumption results from reduced gas exchange losses due to dethrottling and increased thermal efficiency due to lean combustion. In addition to these advantages at part load operation, the mixture preparation procedure and combustion characteristics of a DISI engine provide better knocking characteristics than those of a conventional SI engine with port fuel injection (PFI). This allows the compression ratio of the DISI engine to be increased. The volumetric efficiency can be further improved beyond that of PFI engines because of the faster and more rapid fuel spray vaporisation during the intake stroke, the accompanying decrease in charge temperature, and the increased pressure differences across the intake valves during the intake stroke. Therefore, at full load operation, the DISI engine offers higher power output than the equivalent conventional PFI engine.

Players In the Forefront

Tata Motors, the country’s biggest vehicle maker, is said to be working on reducing the engine size for its diesel vehicles, in the wake of sales restrictions in this regard imposed for the Delhi-National Capital Region. The company is looking to downsize engines to below 2,000cc (Two litres) for its models from its sports and utility vehicle portfolio, to be able to resume sales in these areas.
Few months back, M&M had launched a 1,999cc diesel engine to power its Scorpio and XUV 500 models. This had allowed M&M the utility vehicle market leader, to resume sales of these two models in Delhi. Asked if Tata would be looking at downsizing its engines, a spokesperson from Tata said, “We are working on it because it is the right this for us to consider. We cannot say when it is going to come about but we are certainlly getting ready to deal with that.”
Downsizing of technology is not new to Tata Motors, maker of the Nano, Indica and Safari models. The company also has developed a one-litre diesel engine and a 1.2-litre petrol engine for its yet to be launch model. “If you look at all our engine strategy recently, we have exploited downsizing technology quite strongly. Our new gasoline engine, 1.2 litre, is from downsizing of technology.” said spokesperson from Tata Motors.
Hit by ban of registration of diesel SUVs and cars with engines above 2,000cc in Delhi-NCR, homegrown auto major M&M launched a 1.99 litre version of its mHawk engine series. “This engine would power the New Generation Scorpio as well as the New Age XUV500. It would be available for customers within the Delhi and NCR Region to begin with,” M&M said in a statement.

Mahindra & Mahindra President and Chief Executive, Auto Division Pravin Shah said: “This new engine, the development of which started in August 2014, is now ready for launch on both the New Generation Scorpio and the New Age XUV500.” Previously, these two vehicles were powered by 2.2 litre mHawk engines. The new 1.99 litre engine will power the new generation Scorpio and will deliver 120 HP while for the new XUV500, it will deliver 140 HP, the company said.

In December 2015, Supreme Court had banned registration of new SUVs and cars powered by diesel engines of 2,000cc and above in the Capital and NCR till March 31 in the wake of rising pollution. M&M is among the vehicle manufacturers, which was hit hard by the ban as the Delhi-NCR region accounted for around 2 per cent of its total utility vehicle sales. The company’s popular models, including the XUV500, Scorpio, Xylo and Bolero, have engines above 2000cc. These vehicles are priced in the range of Rs 6.6 lakh to Rs 17.36 lakh (ex-showroom Delhi).

Ashok Leyland showcased in April 2017 the indigenously developed iEGR (intelligent Exhaust Gas Recirculation) technology that helps its trucks and buses to meet BS-IV emission standards and is ideally suited for Indian conditions.

The iEGR is also the secret behind the company not being fazed by the sudden ban imposed by the Supreme Court on sale of BS-III vehicles from April 1st 2017 . It had an inventory of nearly 10,000 BS-III vehicles that could not be sold after the March 31 deadline. But thanks to iEGR, it can simply swap the engines and sell the older version in the after-market, said Vinod Dasari, Managing Director, Ashok Leyland, at the company’s global conference to display its full range of vehicles and solutions.

Globally, two technologies are used for meeting the latest emission standards – SCR, which is used by companies like Daimler, and EGR. Ashok Leyland has brought its indigenous innovation in the EGR technology to not only meet BS-IV emission norms but also ensure reliability. About 200 engineers in its R&D wing worked on developing the new technology.

Elaborating on the advantages of iEGR over SCR technology, Dasari said SCR requires a comprehensive electronic system to manage it. Also, it needs an additional diesel exhaust fluid, which means additional cost. SCR technology is suited for long hauls at constant speed not often available in Indian conditions, he said. Ashok Leyland’s BS-IV vehicles, powered by iEGR technology will have the lowest level of electronics. This will ensure easier serviceability and lower maintenance costs. Also, the technology promises 10 per cent better fuel efficiency than its BS-III trucks. The engines with iEGR can go up to 400 HP.

Many are aware of the collaboration between Mercedes-Benz and Renault-Nissan. Knowing this, one would expect that both companies will come up with something impressive. Sources say that the partnership has been working on some new gasoline four-cylinder engines. However, rather than developing a more powerful engine, they seem to have come up with 1.2- and 1.4-litre engines instead. Why small engines, you might want to ask? The reason behind the downsizing is because the German company aims to lower emissions while increasing the efficiency of the new engines. The new 1.2- and 1.4-litre units will benefit from direct injection, and will be a standard in the next generation base variants of the A-Class and B-Class lineups, according to reports from leading Auto Magazine in India. There are currently eight cars lined up for Mercedes’ compact models for 2018 including: the A-Class hatchback, A-Class Sedan, CLA, CLA Shooting Brake, B-Class, GLA, a rumoured GLB, and an unknown model that has yet to be announced by the company.

The new four-cylinder units, which currently go under the codename M282, are being engineered exclusively for transverse applications. Therefore, these engines will not be available for use in larger Mercedes-Benz models. These new units will be joined by an updated version of the “M274” which will soon be given a codename that is “M260”. The M260 will be bigger and is going to be available in two versions: 1.6- and 2.0-litre units.
Meanwhile, the 381 horsepower (280 kilowatts) and 350 pound-feet (475 Newton-metres) of torque M133 that currently houses in the “45” models will be replaced by the upgraded 2.0-litre unit – which will now serve as a foundation for the range topping models of the following models: A45, CLA45, and GLA45. The 2.0 litre engine can produce a total of
400 horsepower.

Challenges in Downsizing

A set of challenges awaits the industry more so for the auto component suppliers because they are burdened with the onus of supplying a diverse range of components to their respective OEMs, in large quantities to meet the market demand and at the same time, manage their business performance. They can be broadly classified, financial investment, technology adoption, adaptive production management, diverse skill sets and personnel or industrial relations.

Vision Ahead

As published by SIAM, India produced a total of 23.588 million vehicles in all categories, during the period January to December 2015. Further, India is on track in line with AMP 2016-26 jointly released by SIAM, ACMA last year. On a closer look, the envisaged projections are mind boggling but very achievable in light of our government’s relentless drive to create a better economy in the country, accelerate infrastructure developments, faster road building, investment-backed rural development and so on. Above all, this year the monsoon looks good and will contribute to rural buying of automobiles in which engine downsizing is expected to play a major role.

Downsizing Challenges

  • High investments in new technologies
  • Large investments in sophisticated production machines
  • New technology adoption
  • Appropriate software to manage diverse production
  • Revamping production processes.
  • Sourcing alternate materials
  • Continuous skill development
  • Consequently higher wages for workforce
  • Reducing highly skilled workforce attrition
  • Eco-friendly production facilities
  • Zero hazardous effluent discharge
  • Ensuring zero component recall
  • Lack of documented testing and certification standards
  • Reduced turnaround time for changes
  • End-user acceptance
  • Lowering costs
  • Maintaining profitability
  • Managing growth
  • Managing administrative issues

Advantage Downsizing

  • Better fuel economy
  • Lower life cycle costs
  • Highly efficient burning of fuel
  • Reduced carbon footprint
  • Higher power-to-weight ratio
  • Better power response
  • Reduction in unproductive weight
  • Preservation of natural resources
  • Accommodate hybrid and emission control units
  • Increase in passenger space
  • Provides options for better styling of vehicles

This engine would
power the New Generation Scorpio as well as the New Age XUV500.”

– Pravin Shah
President and Chief Executive, Auto Division
Mahindra & Mahindra Ltd.

Ashok Leyland showcased the indigenously developed iEGR technology that helps its trucks and buses to meet BS-IV emission standards.”

– Vinod Dasari,
Managing Director,
Ashok Leyland

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