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ABSTRACT

PROJECT TITLE : VOLKSWAGEN BLUEMOTION TECHNOLOGIES.

PROJECT LOCATION : VOLKSWAGEN INDIA PVT.LTD., PUNE, INDIA.

OUTLINE :

The Research Project named Volkswagen Bluemotion Technologies deals with the understanding of the various innovations that are being implemented in the modern day vehicles. Technologies under the Bluemotion Brand Umbrella include Turbocharging, Direct Injection, Diesel Particulate Filters, Exhaust Gas Recirculation and Automatic Stop-Start Mechanisms. These technologies put together are responsible for the increased vehicle performance, increased fuel efficiency and reduced vehicle emissions.

CONCLUSION :

Thus, the main aim of this project lies at the understanding of these aspects that are put together in a single vehicle. Also, various testing procedures have been performed in order to depict the effectiveness of these advanced technologies over their obsolete counterparts. Thus, all in all, this project acts as an insight to the automobile industry and its advancements planned for the future.

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ABOUT VOLKSWAGEN

The Volkswagen Group is a German Multinational Automotive company headquartered in Wolfsburg, Lower Saxony, Germany. It designs, manufactures and distributes passenger and commercial vehicles, motorcycles, engines, turbo-machinery and offers related services including financing, leasing and fleet management.

In 2012, it produced the third-largest number of motor vehicles of any company in the world, behind General Motors and Toyota. It has maintained the largest market share in Europe for over two decades. As of 2013, it ranked ninth in the Fortune Global 500 list of the world's largest companies.

Volkswagen Group sells passenger cars under the Audi, Bentley, Bugatti, Lamborghini, Porsche, SEAT, Škoda and Volkswagen marques; motorcycles under the Ducati brand; and commercial vehicles under the MAN, Scania, Neoplan and Volkswagen Commercial Vehicles marques. It is divided into two primary divisions, the Automotive Division and the Financial Services Division, and has approximately 340 subsidiary companies.

The company has operations in approximately 150 countries and operates 100 production facilities across 27 countries. It holds a 19.9% non-controlling shareholding in Suzuki and has two major joint-ventures in China. It is one of the most respected and trusted brands across the globe and particularly in India.

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INDEX

EXECUTIVE SUMMARY .............................................................................................4

1. INTRODUCTION. ............................................................................................7

2. TESTING PROGRAM. .....................................................................................9

3. TESTING LOCATIONS .....................................................................................10

4. VEHICLE OVERVIEW ...................................................................................12

5. TESTING PHASE- 1 ......................................................................................27

5.1. RESULTS ............................................................................................................27

5.1.1. 2-Cycle Fuel Consumption Results..................................................................28

5.1.2. 5-Cycle Fuel Consumption Results.............................................................. ...29

5.1.3. Emissions Results............................................................................................31

6. TESTING PHASE - 2........................................................................................32

6.1. ACCELERATION EVALUATION................. .. ..........................................................32

6.2. MAXIMUM SPEED IN GEAR ..................................................................................33

6.3. HANDLING ..................................................................................................... ..34

6.4. NOISE EMISSIONS TESTS ....................................................................................35

6.5. BRAKING................................................ ...........................................................36

6.6. SUMMARY REGARDING DYNAMIC TESTING............................................................37

7. TESTING PHASE- 3..........................................................................................38

8. CONCLUSIONS.................................................................................................39

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EXECUTIVE SUMMARY

Diesel vehicles have come a long way over the past few years. As a result of several technological innovations, modern diesel vehicles are cleaner, less noisy and more efficient than previous generations. Advanced clean diesel vehicles continue to be very cost effective to operate. They can be up to 30% more efficient than traditional gasoline engines, resulting in lower greenhouse gas emissions and reduced fuel consumption in certain applications.

The Volkswagen Polo is a sub-compact passenger vehicle that was designed and built to conform to European specifications. It is powered by a diesel engine with a 1.4-litre inline 3-cylinder turbocharged engine. Winner of the World Green Car of the Year Award in 2008 and 2010, the Polo was included in the list of one of the most innovative vehicles because it incorporates several fuel-conserving and advanced technologies such as direct injection, exhaust gas recirculation, a catalytic coated diesel particulate filter and variable geometry turbine turbo charging.

The Polo was henceforth tested and evaluated to assess the reality of its performance and innovation over three phases:

Laboratory fuel consumption and exhaust emissions. Dynamic track testing. On-road evaluations.

The following is a summary of the results obtained from these evaluations

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Barriers to the Introduction of Advanced Diesel Technologies into the market:

There are two principle market barriers to the introduction of the latest generation of clean diesel vehicles into the market, including:

Consumer misperceptions regarding diesel vehicles;

Exhaust emission limits with which manufacturers must comply.

Consumer Barriers:

The consumer adoption of diesel vehicle technologies more generally, has been low due to a number of barriers, including historical concerns about vehicle reliability, diesel fuel costs, and concerns about noise, vibrations and emissions. Market research suggests that legacy performance concerns, which occurred in the 1970s and 1980s, continue to discourage consumer uptake of diesels today, despite the significant technical progress that has been made in addressing these issues.

In reality, the latest generation of clean diesel technologies, such as those found in the VW Polo Bluemotion TDI, has helped improve the fuel efficiency of diesel vehicles, while reducing vibration and emissions. Despite these technological improvements, the rate of diesel vehicle adoption has remained low because consumers have maintained these historical perceptions.

One of objectives in testing the VW Polo is to help change consumer perceptions by presenting results that demonstrate the real-world performance benefits of clean diesel vehicles– results that directly challenge these perceptions.

Regulatory Barriers:

Exhaust emission and crash test standards differ in several areas. As a result, many European vehicle models, such as the VW Polo, cannot be approved for the Indian market without performing additional compliance testing and/or vehicle modifications.

While vehicle manufacturers are responsible for choosing the suite of vehicles and technologies they introduce in the market, the introduction of these new technologies helps increase market demand through consumer outreach, and undertaking testing to demonstrate the potential of these new technologies.

Thus, the prime aim of this study is to get an in depth look at the technologies involved in the Bluemotion badge and its fleet of vehicles which can be deemed to be good and efficient for the market through rigid and thorough testing.

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CHAPTER-1 INTRODUCTION

1.0. INTRODUCTION

Diesel vehicles have come a long way over the past few years. As a result of several technological innovations, modern diesel vehicles are cleaner, less noisy and more efficient than previous generations. Advanced clean diesel vehicles continue to be very cost effective to operate. They can be up to 30% more efficient than traditional gasoline engines, resulting in lower greenhouse gas emissions and reduced fuel consumption in certain applications.

Modern diesels are equipped with a variety of advanced technologies that reduce harmful by-products of combustion, including particulate matter and nitrogen oxides. For example, innovations include exhaust gas recirculation, diesel particulate filters, common rail direct injection, selective catalytic reduction and diesel exhaust fluid.

The Polo Bluemotion TDI is equipped with several technologies to reduce fuel consumption technologies such as Variable Geometry Turbo Charging (VGT), Exhaust Gas Recirculation (EGR), advanced aerodynamics, low rolling resistance tires and a diesel particulate filter. The Polo also captured attention when it was awarded the World Green Car of the Year.

Fig.1.1. Growth rate of Bluemotion TechnologyThe Bluemotion miracle:

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Greater efficiency, lower emissions and no loss of driving pleasure are the benefits under the Umbrella brand of Bluemotion Technology. Volkswagen offers technologies and products that make for environmentally compatible mobility coupled with dynamism and everyday usability.

TSI engines are one of the basic technologies that make a key contribution to the brand. Bluemotion Technologies stand for the interaction of a large number of innovations such as TDI, TSI and DSG, which ensure mobility with lower fuel consumption and pollutant emissions.

The highlights of Bluemotion Technologies include the sub-brands TSI EcoFuel, BlueTDI and Bluemotion, as well as the models with the Bluemotion Technology badge. The technical innovations that contribute to lower fuel consumption include Start-Stop systems, Regenerative Braking and Direct-Shift Gearbox (DSG) transmissions, as well as economical TSI engines.

TSI technology is also a key component in the Powertrain and Fuel Strategy pursued by Volkswagen in its efforts to achieve sustainable mobility in the future. The major objectives are to reduce local emissions and concentrations of the greenhouse gas carbon dioxide, as well as to lay the foundations for secure energy supplies. In the future, vehicles will certainly be powered by the zero emission electric motors that engineers are already developing.

In the medium term, however, the internal combustion engine will remain the dominant powertrain technology. TDI and TSI engines already represent efficient, environmentally compatible technologies that achieve their full potential in combination with innovative DSG transmissions and a start-stop system of the type already used in a number of Bluemotion-Technology models.

Fig.1.2. Bluemotion Technology- The Umbrella Brand

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CHAPTER- 2 THE TESTING PROGRAM

2.0. TESTING PROGRAM

The Polo was tested and evaluated over three distinct phases:

Laboratory fuel consumption and exhaust emissions. Dynamic track testing. On-road evaluations.

Together, these various phases were designed to realistically assess the vehicle’s overall performance and identify any possible barriers that may negatively impact the introduction of the various advanced technologies featured in the Polo into the Global market.

The Polo was evaluated using standard testing procedures based on practices used by theCorporate Average Fuel Consumption (CAFC), the Department of Transport, the International Standards Organization and The Society of Automotive Engineers.

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CHAPTER- 3 THE TESTING LOCATIONS

3.0. TESTING LOCATIONS

Phase-I testing was performed at the Volkswagen India Research Division (V.I.R.D) located in Pune, Maharashtra. All fuel consumption and exhaust emissions testing were performed in a controlled laboratory, using a vehicle chassis dynamometer.

The laboratory environment ensured that testing was completed to within ± 1 degree Celsius of the required test temperature. Additionally, the vehicle was tested over several separate driving cycles and was maintained to within a ± 1.5 km/h limit of the required speed.

Phase-II testing was performed at the test track facility available at Volkswagen India, Pune. The closed test track environment was necessary to ensure that testing was performed in a controlled setting and under controlled conditions. The test track is equipped with over 2.5 kilometres of road, including both a high-speed and low-speed circuit, to allow for a variety of tests.

Phase-III comprised on-road evaluations performed by the Safety Department at Volkswagen India, Pune.

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Fig.3.1. Picture of the Research Centre and the Test track at Volkswagen India, Pune.

Thus, effective testing under perfect conditions was done in order to achieve the best results fit for the global market.

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CHAPTER- 4 VEHICLE OVERVIEW

4.0. TECHNICAL OVERVIEW

The Polo, classified as a sub-compact vehicle, is equipped with a 1.4-litre inline 3-cylinder Turbocharged engine. The vehicle’s engine power train is equipped with several environmentally friendly technologies such as exhaust gas recirculation, which helps to reduce nitrogen oxides, a by-product of diesel combustion.

As well, the 5-speed manual transmission, with longer gear ratios in gears 3 through 5, provides fuel savings during periods of high speed cruising. The Variable Turbine Geometry Turbocharger helps to provide additional power over a longer range of engine speeds.

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The vehicle’s aerodynamics have been optimized to include a front fluidic spoiler and a roof spoiler, which results in a low drag coefficient of 0.30. Furthermore, the vehicle is equipped with low rolling resistance tires. Together, these features help the vehicle slip and roll through the air and on the road more easily.

The basic components of the Bluemotion Polo TDi are described in detail.

4.1. SYSTEMS OVERVIEW

Exhaust Gas Recirculation System:

On the 1.4L TDI engine, the Exhaust Gas Recirculation Valve and the Exhaust Gas Cooler with Exhaust Gas Flap have been combined into a single module. The advantages of the modular design are a compact space requirement and, at the same time, a shorter control path.

The exhaust gas recirculation module is bolted to the exhaust side of the cylinder head and the exhaust manifold. The module is connected to the intake manifold directly through the cylinder head. This allows additional cooling of the Re-circulated Exhaust Gases.

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Fig.4.1. The Exhaust Gas Recirculation Unit in a Bluemotion TDi Engine

Design of the Exhaust Gas Recirculation Unit:

Fig.4.2. Design of the Exhaust gas Recirculation Unit

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Function of the Exhaust Gas Recirculation Unit:

The exhaust gas recirculation helps reduce nitrogen oxide emissions. Part of the exhaust gases are returned to the combustion process.

The recirculation quantity is regulated by the engine control unit taking the engine speed, intake air quantity, intake air temperature, injection quantity and air pressure into account.

Fig.4.3. System Overview of an Exhaust Gas Recirculation Unit

Legend:

G39 Lambda probe

G62 Coolant temperature sender

G69 Throttle valve potentiometer

J338 Throttle valve module

J623 Engine control unit

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N18 Exhaust gas recirculation valve

N345 Exhaust gas recirculation cooler change-over valve

A Exhaust gas recirculation module

B Vacuum unit

C Catalytic converter

Diesel Particulate Filters:

The reduction of particulate emissions from diesel engines is a great challenge in this day and age. In addition to engine measures, exhaust gas treatment is of particular importance to help achieve this. The particulate filter is an effective method to remove carbon soot particles that are inherent in diesel emissions.

The most common filter systems comprise of an oxidisation catalyst and a particulate filter. On the catalytic coated particulate filter, the catalyst and filter have been combined to form one single unit. With this particulate filter system, the particulates can be burnt off continually without the addition of a fuel additive, thanks to the design and installation position close to the engine.

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Fig.4.4. The Catalytic Coated Diesel Particulate Filter

Emissions standards

In the Republic of Germany, across Europe and throughout the world, laws have been passed in recent years to reduce the emission of harmful substances in the air. In Europe, the emissions standards are categorised from EU1 to EU6. These prescribe emission limits to the automobile industry for type approval of new vehicle models.

EU3: From the year 2000, newly registered vehicles have to fulfil emissions standard EU3.It differs from its predecessor EU2 by more stringent conditions on the test bed and by a reduction in the limit values.

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EU4 : The EU4 standard came into force in 2005 and superseded EU3. The consequences are a further reduction in permissible limit values. Even now, more than 65 percent of all newly registered vehicles with a diesel engine fulfil emissions standard EU4.

Fig.4.5. Permissible pollutant values of Diesel Engine Exhaust gases.

The harmful products of fuel combustion cause great harm to the atmosphere and living creatures. The various gases that exist in an automobile exhaust are as follows.

Fig.4.6. Pie Chart illustrating the composition of pollutants in Exhaust gases

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The particle filter

The Catalytic Coated Diesel Particulate Filter is located in the exhaust system after the turbocharger, within close proximity of the engine. Two components, the oxidisation catalyst and the particulate filter, have been combined to form one unit, the catalytic coated diesel particulate filter. It joins the functions of the oxidisation catalyst and the diesel particulate filter in one single component.

Fig.4.7. Catalytic Coated Diesel Particulate Filter

Fig.4.8. Catalytic Coated Diesel Particulate Filter schematics

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As a diesel particulate filter it filters out the carbon soot particles from the exhaust gas. In its function as oxidisation catalyst, it cleans the exhaust gas of hydrocarbons (HC) and carbon monoxide (CO). They are converted into water (H2O) and carbon dioxide (CO2).

The diesel particulate filter comprises of a honeycomb ceramic matrix made from silicon carbide, which can be found in a metal housing. The ceramic matrix itself has many small channels that run parallel to each other and are alternately connected. In this way, inlet and outlet channels are created that are separated by filter walls.

The filter walls made from silicon carbide are porous. The silicon carbide body is coated with a mixture of aluminium oxide and ceroxide. This mixture serves as a carrier layer for the catalytic converter. The carrier layer is coated with a precious metal, platinum, which acts as the catalyst. A catalyst is a substance that promotes or hinders a chemical reaction without changing itself.

Fig.4.9. Interior Design of a D.P.F. Function

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Since the channels are sealed alternately in the direction of flow from the inlet and outlet side, the carbon soot contaminated exhaust gas must flow through the porous filter walls made from silicon carbide. When this happens, the carbon soot particles and not the gaseous components are retained in the inlet channels.

Regeneration

The diesel particulate filter must be cleaned of the particles of carbon soot regularly to prevent it from becoming blocked and its function thereby being affected. During the regeneration phase, the particulates that have accumulated in the particulate filter are burnt off (oxidised). With regeneration of the catalytic coated particulate filter, passive regeneration and active regeneration are separated. There are no signs to the driver that regeneration is occurring.

Passive regeneration

With passive regeneration, the carbon soot particles are burnt off continually without intervention from the engine management system. The particulate filter is positioned in close proximity to the engine. This assures that exhaust gas temperatures of 350-500 °C are reached on motorways, for example.

The carbon soot particles are thereby converted into carbon dioxide by a reaction with nitrogen oxide. This gradual process occurs slowly and continually through the platinum coating, which works as a catalyst.

Fig.4.10. Passive Regeneration in a D.P.F.Active regeneration

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With active regeneration, the carbon soot particles are burnt off through a targeted increase in the exhaust gas temperature by the engine management system. In urban traffic with low loads on the engine, the exhaust gas temperatures for passive regeneration of the particulate filter are too low. Since the carbon soot particles cannot be broken down, deposits build up in the filter.

As soon as a certain level of carbon soot deposits is reached in the filter, active regeneration is initiated by the engine management system. This process lasts for approximately 10 minutes. The carbon soot particles are burnt off to carbon dioxide at an exhaust gas temperature of 600-650 °C.

Fig.4.11. Active Regeneration in a D.P.F.

Supercharger:

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The supercharger is a mechanical charger that is activated by a magnetic clutch.

Advantages

- Faster build up of boost pressure

- High torque at low revs

- Only activated when required

- No external lubrication and cooling necessary

Disadvantage s

- Requires drive power from engine

- Boost pressure is produced at any engine speed and is then regulated with part of the generated power being lost again

Fig.4.12. A Supercharger in a TDi EngineTurbocharger:

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The turbocharger is constantly powered by the exhaust gas.

Advantages

- Very good efficiency due to use of exhaust gas energy.

Disadvantages

- In a small engine, the boost pressure produced in the low rev ranges is not sufficient to generate high torque.

- High thermal loading.

Fig.4.13. A Turbocharger in a TDi Engine

Schematic diagram of all supercharging components

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The schematic diagram shows the basic set-up of the “dual-supercharging” system and the path of the fresh intake air.

Fig.4.14. Schematics of a Supercharger/ Turbocharger in a TDi Engine

Exclusive turbocharger boost range

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In the green area, the turbocharger manages to produce the necessary boost pressure on its own. The boost pressure is controlled by the charge pressure control solenoid valve.

Fig.4.15. Boost Range of a Turbocharged Engine

Thus, these are the various components, specifications, features and specialities of the Bluemotion Technology that is to be implemented in the market. The various features described in this chapter contribute to the vehicle overview.

CHAPTER- 5

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TESTING PHASE- 1

5.0. LABORATORY FUEL CONSUMPTION AND EMISSIONS TESTING

More than 3,500 kilometres of vehicle and engine use were accumulated on the Polo. The procedure outlines the prescribed route that the vehicle must follow, using diesel fuel that is commercially available (<15 ppm of sulphur). Once mileage accumulation was completed fuel consumption and emission tests were performed.

Before beginning, the vehicle was kept at a laboratory temperature for no less than 8 hours before each test. This is to ensure that the vehicle may be compared against other test vehicles undergoing the same emissions and fuel consumption evaluations, and that all mechanical components and fluids reach the chosen temperature by the time of testing.Evaluations were then performed over five duty cycles.

The vehicle was mounted on a chassis dynamometer where the front (drive) wheels were allowed to roll against a resistance drum. The drum’s resistance was pre-programmed based on the vehicle’s road load force parameters. Parameters and coefficients were based on a vehicle travelling from a speed of 115 km/h to 15 km/h (71.5 mph to 9.3 mph) while coasting. The final result was a model for road load force as a function of speed, during operation on a dry, level road, under reference conditions of 20°C (68°F) and 98.21 kPa (29.00 in-Hg), with no wind or precipitation and with the transmission in neutral.

The emissions data were analyzed for:

Carbon monoxide

Carbon dioxide

Total hydrocarbons

Nitrogen oxides

Particulate matter.5.1. RESULTS

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The fuel consumption estimate for the Polo is based on calculations for the 2-cycle city and highway driving cycles and the five-cycle city, highway, cold test, aggressive driving and electrical load driving cycles. The test cycles were developed based on extensive real world data, such as driving activity, trip length and stopping frequency, among other factors.

The 2-cycle value was calculated by adding the results for the urban driving cycle and the highway duty cycle, using a ratio of 55% city to 45% highway. The cycles were then adjusted upward 10% and 15% respectively to account for a variety of “real-world” driving factors. The adjustments are meant to account for differences between the way vehicles are driven on the road and over the test cycles.

The end result is a combined fuel consumption rating for the vehicle, in addition to separate city and highway results.

The 5-cycle method includes testing over a wider range of driving patterns and temperature conditions than those tested in the 2-cycle calculation. For example, in the real world, vehicles are often driven more aggressively and at higher speeds than the existing city and highway test cycles can duplicate.

Using the 5-cycle method, therefore, offers a more accurate representation of the vehicle’s fuel consumption and overall performance than the 2-cycle method. Both methods apply adjustment factors to take into account other real-world driving factors such as road grade, wind, low tire pressure and fuel quality. However, because it takes other factors into account, for the same make and model, the 5-cycle method results in fuel consumption values that are approximately 10 to 20% higher than those for the 2-cycle method.

5.1.1. 2-Cycle Fuel Consumption Results

The Polo was tested in two highway cycles, according to current market standards for fuel consumption testing. The results were averaged for each cycle.

Based on the 2-cycle calculations and using the correction factors listed above, the results for the fuel consumption of the Polo are 5.28 L/100km for the city and 3.64 L/100km for the highway. The combined fuel consumption value, using a 55% and 45% weighting for the city and highway respectively, is 4.54 L/100km.Figure below shows the unadjusted combined fuel consumption value of 4.03 L/100km versus the average.

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It can be seen that the Polo is more than 50% below the standard consumption of 8.60 L/100 km and more than 40% below the actual average achieved by all new cars.

Fig.5.1. 2-Cycle Fuel Consumption Graph

5.1.2. 5-Cycle Fuel Consumption Results

Each of the 5-cycles is divided into “phases” – also referred to as “bags” because each phase sample is bagged and analyzed separately, without interruption, during the test. Under the vehicle-specific 5-cycle formula, the highway fuel economy value is calculatedas follows:

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The results for the fuel consumption of the Polo, based on the 5-cycle calculations above, are 5.90 L/100km for the city and 4.24 L/100km for the highway. The 5-cycle testing values may provide a more accurate representation of what a user can expect for fuel consumption in real-world driving.

When compared against the city and highway values for the 2-cycle calculation, the 5-cycle fuel consumption values are 11% and 16% higher for city and highway driving respectively.

The following table shows us the representation of the fuel economies of the Bluemotion Polo TDi.

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5.1.3. Emissions Results

The results of the city and highway test cycles offer a combined CO2 emissions value of109 g/km. The two best performing comparable subcompact vehicles for the same model year, obtained CO2 emissions value of 152 g/km CO2. Thus technologies such as those being offered in the VW Polo could offer a 29% reduction in CO2 emissions over the current best performers in the sub-compact class.

When compared to the national average for all sub-compact cars available, the CO2 emissions reported for the same model year are 238 g/km. The Polo, therefore, offers a 55% improvement in CO2 emissions over all comparable models.

Thus, this completes the phase-1 of the testing procedure. The 2nd stage involves the dynamic testing of the Bluemotion Technology at the heart of the Polo TDi.

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CHAPTER- 6 TESTING PHASE- 2

6.0. DYNAMIC TESTING

The Polo underwent dynamic and performance testing. Most aspects of the tests performed were for general dynamic assessment purposes.

6.1. ACCELERATION EVALUATION

The maximum acceleration was determined by starting the vehicle from a standing start and following the procedure set out below.

1. The vehicle was evaluated by accelerating to the maximum attainable speed in a quarter of a mile (402.3 m).

2. The vehicle was evaluated by accelerating to the maximum attainable speed in a kilometre (1000 m).Shifting occurred at what was determined to be an optimal shift point.

To account for variation in wind, the vehicle was driven in both directions on the test track, with the results averaged.

6.2. MAXIMUM SPEED IN GEAR

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The maximum speed attainable was tested and recorded for each gear. The driver started from a standing start for first gear only. The vehicle was accelerated, changing gears only when the vehicle engine speed had operated at its maximum peak rpm for at least 3 seconds.

The maximum speed and revolutions per minute for each gear was recorded.

During testing, the Polo reached a maximum speed of 168.2 km/h in approximately 80 seconds, while operating in 5th gear. Thus, the Polo has the ability to meet and exceed all minimum speed requirements on public roads of the country. Additionally the torque and acceleration compare favourably to typical results in the sub-compact class.

The maximum speed and the speed in each gear is shown graphically in one direction before being average, are shown graphically.

Fig.6.1. Maximum speed corresponding to the appropriate gear graph

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6.3. HANDLING

The lateral skid pad test is used to determine the maximum speed that the Polo could achieve in a cornering situation. When the vehicle reaches its cornering limit, it will either under-steer or over-steer, losing traction on the curve. When the vehicle had almost lost traction, the maximum lateral acceleration was recorded.

In order to measure vehicle displacement, speed and lateral acceleration, the Polo was equipped with a combined GPS and accelerometer-based data acquisition system. All measurements refer to the vehicle’s centre of gravity.

Tires were warmed up and conditioned by using a sinusoidal steering pattern at a frequency of 1 Hz, peak steering-wheel angle amplitude corresponding to a peak lateral acceleration of 0.5–0.6 g, and a speed of 56 km/h. The vehicle was driven through the course four times, performing 10 cycles of sinusoidal steering during each pass.

Testing was performed under the following conditions:

The vehicle was equipped with new tires.

Tire pressure was adjusted to conform to the manufacturer’s recommendations.

The vehicle’s weight was adjusted to its lightly loaded condition.

The skid pad was 61 m in diameter.

The maximum speed that the vehicle can achieve in a cornering situation is 61 km/h. Higher speeds resulted in a loss of traction (under steering).

6.4. NOISE EMISSIONS TESTS

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Noise is of concern with diesel vehicles. There is often a complaint with regard to the amount of noise they emit in comparison with gasoline vehicles. In order to measure the noise emitted from the engine and exhaust, microphones were set up in the vehicle.

The test procedure for the acceleration tests was as follows:

When the vehicle approached a speed of 48 km/h ± 1.2 km/h, the speed was stabilized before the acceleration point.

At the acceleration point (± 1.5 m), as rapidly as it was possible to establish, the throttle was opened wide.

Acceleration continued until the entire vehicle had exited the test zone.

The sound meter was set to fast dB(A).

Generally 60 dB is considered to be the level of normal human conversation while 90 dB would be the sound generated by a typical lawn mower.

The low levels of sound measured for the Polo were the proof to how quiet diesel engines have become as a result of engineering and design improvements and years of refining vehicle design.

Most of the noise being generated from the vehicle at these speeds is due to tire and wind resistance, which is acceptable and similar across any vehicle power train platform.

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Thus, the Polo Bluemotion TDi achieved quieter vehicle noise levels when compared to the older diesel powered vehicles with a maximum sound level reaching 78.6 dB at the redline of the vehicle during full acceleration.

6.5. BRAKING

Testing was performed according to procedures. The results were tabulated as follows.

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Fig.6.2. Braking Performance of the Bluemotion Polo TDi

6.6. SUMMARY REGARDING DYNAMIC TESTING

Overall, the dynamic test results show that the Volkswagen Polo Bluemotion TDI meets the relevant global standards. All aspects of handling and performance were either good, pass or acceptable relative to the sub-compact class, and its dynamic performance was similar to that of market competitors in its class. In addition it met all aspects of noise and braking standards.

Thus, the Bluemotion Technology has been proven successful at the global stage through the dynamic testing procedure. The next procedure involves the 3rd phase of testing i.e., on-road evaluations.

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CHAPTER- 7 TESTING PHASE- 3

7.0. ON-ROAD EVALUATIONS

The team and staff members of the Safety Department evaluated the Polo’s performance. Several departmental safety inspectors operated the vehicle in various conditions.

Drivers and occupants of the vehicle commented that the Polo was unbelievably quick and smooth for a 3-cylinder vehicle. Also, drivers appreciated the initial torque offered at low rpm, meaning that they were able to accelerate quickly from a stopped start. Of interest was also how much interior space was available for a sub-compact vehicle, including the headroom.

However, users also commented on the vibration produced by the diesel engine and how it was significantly more noticeable than in a gasoline engine, especially when stopped or idling. Because the Polo is equipped with unit-pump injectors rather than common rail direct injection, this is to be expected.

As well, users commented on the need to accelerate higher through gears 4 and 5, as they are very long. This again is expected since the transmission is set up to have longer gear ratios through gears 3, 4 and 5, in order to offer significant fuel savings while cruising. Over 5,000 km of evaluations were performed on this vehicle, with an average real-world fuel consumption of 5.1 L/100km being reported.

Lastly, the evaluators enjoyed driving with a turbo, some for the first time. They were able to experience firsthand the results of a Variable Geometry Turbocharger, which contributes to the increased power and the fuel savings that a small, clean diesel engine is able to offer due to such improvisations in Technology; The Bluemotion Technology.

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CHAPTER- 8 CONCLUSIONS

8.0. CONCLUSION

Diesel vehicles have come a long way over the past few years. They are no longer noisy and polluting, and they continue to be very cost effective to operate. Based on an average of 20,000 km of driving per year and fuel costs of Re.50/L, fuel cost for the Polo would be approximately Rs.50,000 per year.

As well, the Polo leaves a low carbon footprint of 2,700 kg of CO2 emissions per year emitted from the tailpipe (based on 20,000 km driven annually).

In combined city and highway tests, the Polo’s emissions value is 109 g/km. This is 29% lower than the two most fuel-efficient sub-compacts currently available globally.

The acceptance of several unique technologies, including a transmission optimized to maximize fuel economy and a variable geometry turbocharger (VGTs) are tested and proven and shall soon be accepted by the mass majority of people buying cars.

Turbochargers have been used by manufacturers to improve engine performance in terms of power. Turbocharging an engine allows manufacturers to reduce overall engine displacement and improve fuel efficiency, while maintaining peak power output. However, traditional turbochargers often result in moments of lag between the time additional power is demanded through the accelerator and the moment when the turbo spools up enough to provide the extra power. This ‘turbo lag’ sometimes results in a poorer driving experience.

VGTs, however, have been designed to minimize lag by dynamically controlling airflow across the turbo’s foils. While this technology has been used in larger displacement engines in heavy duty vehicles for many years, the Polo is the first example of its use in a small displacement diesel engine.

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In addition, the vehicle was equipped with a transmission optimized to reduce fuel consumption and emissions. Drivers quickly become accustomed to this configuration, which does not impede vehicle performance.

The feedbacks from various tests did not include any concerns about particulate matter (or soot), an area where consumers traditionally have concerns about diesel technology. Presumably, the vehicle’s on-board particulate filter and other emissions control technologies, such as exhaust gas recirculation, were able to reduce diesel emissions to levels that drivers felt were comparable to those of gasoline-powered vehicles.

Thus, with all these points considered as positives, the BLUEMOTION TECHNOLOGY POWERED POLO 1.4L TDi is a tested piece of technological advancement and is definitely a step forward in the evergreen field of Automobile Engineering.