CNG stands for Compressed Natural Gas. It is one of the most viable alternatives to traditional fuel energy resources (petrol) for the automotive industry. CNG is low in pollutants, high in calorific value and heat yield, economical and available in abundance globally.
Reasons for switching over to this alternate fuel are mainly:
1. Economic benefit: The cost of CNG is almost a third of the cost of Petrol in terms of calorific value resulting in substantial saving in fuel cost, and investment on the CNG kit is paid back in a short period
2. Environment friendly: The use of CNG as a fuel reduces vehicular exhaust emissions significantly. Carbon Monoxide emissions are reduced by 70 to 90% and Hydrocarbon emissions by 40 to 60% as compared to vehicles that use the conventional fuel - Petrol. Carbon Dioxide emissions, a cause for global warming, are also reduced significantly by 10%
3. 100% Income Tax Depreciation: Corporate Organisations, firms, etc. can claim 100% depreciation on a CNG Conversion Kit as this is a pollution controlling equipment. Organisations that buy CNG Conversion Kits should consult their Income Tax Consultants and avail of the depreciation benefits
4. Flexibility and ease of use: The basic engine characteristics of a vehicle are retained while converting it to run on CNG. The vehicle therefore is capable of running either on Petrol or CNG at the flick of a switch on its dashboard.
CNG is becoming popular in India as it is enviromental friendly and 1/3 price of petrol. It now used mostly by trucks, buses and tourist vehichles but as time is passing more and more private cars are getting on CNG. Once the frequency and avalability of this CNG gas station increases more and more cars will be having it.
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Thursday, January 29, 2009
Know your MPFi Car Systems
Ever since the first single-cylinder petrol engine driven Car appeared on the roads during late 19th century, a ‘Carburettor’ became synonymous with it. Later on with the advent of multi-cylinder Engines, so did the ‘Distributor’ or ‘Delco’s.
During the last Century, both evolved considerably – till the ‘Euro-II’ like Pollution Norms got the better of them. For, the Carbs worked on a fundamental principle of ‘reaction’, which could easily get stifled for many reasons. Whereas man, wanted to be literally in the Driver’s Seat – as always.
And thus, as the cliché of necessity being the mother of invention goes, a System of ‘controlled-feeding’ of Fuel + Air + Ignition Spark to the ICE Cylinders in the early ‘80s evolved. A ‘system’ like that had to be based on the engine’s ‘needs of the moment’, such as the load on it, its rpm, vehicle’s road speed etc.
Such a ‘system’ had to ensure that the ‘ob-Nox-ious’ Pollutants were kept to a bare minimum all over it’s operating range – not to mention squeezing the maximum ‘mileage’ out of the last drop of fuel that went into it. Thus ‘fuel-injection’ systems were born – replacing nearly a century old Carburettors.
For the uninitiated, ‘MPFi’ stands for ‘Multi point fuel injection’. Such a system ‘injects’ fuel into individual cylinders, based on commands from the ‘on board engine management system’ Computer – popularly known as the Engine Control Unit or the ECU.
MPFi Systems can either be: a) ‘Sequential’ i.e. direct injection into individual cylinders against their suction strokes, or b) ‘Simultaneous’ i.e. together or all the four or whatever the number of cylinders, or c) ‘Group’ i.e. into Cylinder-Pairs.
These techniques result not only in better ‘power balance’ amongst the cylinders but also in higher output from each one of them, along with faster throttle response.Of these variants of MPFi, ‘Sequential’ is the best from the above considerations of power balance/output.
‘SEFi’’, as advertised by Ford, stands for ‘Sequential Electronic Fuel Injection’, which technically is the best of the above variants of ‘MPFi’. Hyundai/Maruti ‘MPFi’ systems are in fact ‘SEFi’ too. The erstwhile Cielo’s and Matiz’s had the (b) or (c) variants of above MPFi systems.
On the other hand, older Opel-Astra’s had a ’single point’ fuel injection system, which is in between an Mpfi and the now obsolete Single-Carburettor systems.
The ‘Fuel Injectors’ are precision built ‘Solenoid Valves’, something like Washing Machine Water inlet Valves. These have either single or multiple ‘Orifices’ which ‘spray’ fuel into the Fuel inlet manifold of a Cylinder upon actuation, from a common Rail/Header pressurised to around 3 bar, fed by a high pressure electrically driven fuel pump inside the Petrol tank of the Car.
The ‘on-board’ ECU primarily controls the Ignition Timing and quantity of fuel to be injected. The latter is achieved by means of controlling the ‘duration’ for which the Injector solenoid valve coil is kept energized – popularly known as the ‘pulse-width’.
In general, an ECU in turn is controlled by the ‘data input’ from a set of ‘SENSORS’ located all over the Engine and its Auxiliaries. These detect the various ‘operating states’ of the Engine and the performance desired out of it. Such Sensors constantly monitor: 1. Ambient Air Temperature, 2. Engine/Coolant Temp., 3. Exhaust/manifold temp., 4. Exhaust ‘O2’ content, 5. Inlet manifold vacuum, 6. Throttle position, 7. Engine rpm, 8. Vehicle road speed, 9. Crankshaft position, 10. Camshaft position, etc.
Based on a ‘programmed’ interpretation of all this input data, the ECU gives the various ‘commands’ to the Engine’s fuel intake and spark ignition timing systems, to deliver an overall satisfactory performance of the Engine from start to shut down, including ‘emission control’.
This/Part-1 of a 4-part Article is an attempt to familiarise the average ‘BS-II/III’ Car Owner as to what actually lies beneath their Bonnets. In Part-2, we’ll talk about the do’s and don’ts relating to MPFi Cars. In Part-3, for the more curious ones, we’ll see how the stuff works and in Part-4, we’ll explore the commonly encountered problems and DIY-Trouble Shooting.
Immediately, to get the best out of an MPFi System, one should always use – a) The OE recommended Petrol Additives with the ‘Regular’ Unleaded or the new generation ‘Premium’ Petrol’s and b) NEVER Tamper with the OE Wiring Harness of the Car – EVEN to install the ubiquitous Music System OR any other Electrical Accessory - other than those ‘approved’ by the OEM/Dealer and ‘installed’ by him, as these are designed to suit the Car’s OE Central Wiring Harness ‘Couplers’ provided for the purpose. ‘BUTCHERING’ OF THE OE-CWH IS AN ABSOLUTE TABOO FOR MPFI CARS.
Source:
During the last Century, both evolved considerably – till the ‘Euro-II’ like Pollution Norms got the better of them. For, the Carbs worked on a fundamental principle of ‘reaction’, which could easily get stifled for many reasons. Whereas man, wanted to be literally in the Driver’s Seat – as always.
And thus, as the cliché of necessity being the mother of invention goes, a System of ‘controlled-feeding’ of Fuel + Air + Ignition Spark to the ICE Cylinders in the early ‘80s evolved. A ‘system’ like that had to be based on the engine’s ‘needs of the moment’, such as the load on it, its rpm, vehicle’s road speed etc.
Such a ‘system’ had to ensure that the ‘ob-Nox-ious’ Pollutants were kept to a bare minimum all over it’s operating range – not to mention squeezing the maximum ‘mileage’ out of the last drop of fuel that went into it. Thus ‘fuel-injection’ systems were born – replacing nearly a century old Carburettors.
For the uninitiated, ‘MPFi’ stands for ‘Multi point fuel injection’. Such a system ‘injects’ fuel into individual cylinders, based on commands from the ‘on board engine management system’ Computer – popularly known as the Engine Control Unit or the ECU.
MPFi Systems can either be: a) ‘Sequential’ i.e. direct injection into individual cylinders against their suction strokes, or b) ‘Simultaneous’ i.e. together or all the four or whatever the number of cylinders, or c) ‘Group’ i.e. into Cylinder-Pairs.
These techniques result not only in better ‘power balance’ amongst the cylinders but also in higher output from each one of them, along with faster throttle response.Of these variants of MPFi, ‘Sequential’ is the best from the above considerations of power balance/output.
‘SEFi’’, as advertised by Ford, stands for ‘Sequential Electronic Fuel Injection’, which technically is the best of the above variants of ‘MPFi’. Hyundai/Maruti ‘MPFi’ systems are in fact ‘SEFi’ too. The erstwhile Cielo’s and Matiz’s had the (b) or (c) variants of above MPFi systems.
On the other hand, older Opel-Astra’s had a ’single point’ fuel injection system, which is in between an Mpfi and the now obsolete Single-Carburettor systems.
The ‘Fuel Injectors’ are precision built ‘Solenoid Valves’, something like Washing Machine Water inlet Valves. These have either single or multiple ‘Orifices’ which ‘spray’ fuel into the Fuel inlet manifold of a Cylinder upon actuation, from a common Rail/Header pressurised to around 3 bar, fed by a high pressure electrically driven fuel pump inside the Petrol tank of the Car.
The ‘on-board’ ECU primarily controls the Ignition Timing and quantity of fuel to be injected. The latter is achieved by means of controlling the ‘duration’ for which the Injector solenoid valve coil is kept energized – popularly known as the ‘pulse-width’.
In general, an ECU in turn is controlled by the ‘data input’ from a set of ‘SENSORS’ located all over the Engine and its Auxiliaries. These detect the various ‘operating states’ of the Engine and the performance desired out of it. Such Sensors constantly monitor: 1. Ambient Air Temperature, 2. Engine/Coolant Temp., 3. Exhaust/manifold temp., 4. Exhaust ‘O2’ content, 5. Inlet manifold vacuum, 6. Throttle position, 7. Engine rpm, 8. Vehicle road speed, 9. Crankshaft position, 10. Camshaft position, etc.
Based on a ‘programmed’ interpretation of all this input data, the ECU gives the various ‘commands’ to the Engine’s fuel intake and spark ignition timing systems, to deliver an overall satisfactory performance of the Engine from start to shut down, including ‘emission control’.
This/Part-1 of a 4-part Article is an attempt to familiarise the average ‘BS-II/III’ Car Owner as to what actually lies beneath their Bonnets. In Part-2, we’ll talk about the do’s and don’ts relating to MPFi Cars. In Part-3, for the more curious ones, we’ll see how the stuff works and in Part-4, we’ll explore the commonly encountered problems and DIY-Trouble Shooting.
Immediately, to get the best out of an MPFi System, one should always use – a) The OE recommended Petrol Additives with the ‘Regular’ Unleaded or the new generation ‘Premium’ Petrol’s and b) NEVER Tamper with the OE Wiring Harness of the Car – EVEN to install the ubiquitous Music System OR any other Electrical Accessory - other than those ‘approved’ by the OEM/Dealer and ‘installed’ by him, as these are designed to suit the Car’s OE Central Wiring Harness ‘Couplers’ provided for the purpose. ‘BUTCHERING’ OF THE OE-CWH IS AN ABSOLUTE TABOO FOR MPFI CARS.
Source:
On converting Petrol cars to LPG/CNG
LPG is acknowledged the world over as a superior fuel for Automobiles compared to Gasoline/CNG. Consequently, over 10 million Cars are running satisfactorily on LPG around the world as of today - from the lowliest of Cabs to the British Queen’s Rolls-Royce!
A ‘Street-Legal’ LPG Kit for an Mpfi Car will cost you ~ Rs: 35k and ~ 25k for a Carb type. An equivalent CNG Kit may cost ~ Rs: 5k more, coz of the more expensive Cylinder. So one must do one’s cost/benefit analysis first - on the basis of, say, a pay back period of one year. Running your Car on ‘Domestic’ LPG Cylinders is not only illegal but also extremely dangerous.
As a thumb rule, one stands to save about 45% of petrol bill costs with LPG and 65% with CNG. At the same time, one stands to lose about 10% of the engine power also, due to gaseous nature of these fuels and this can cause problems with AC running during peak of summers on cars smaller than 1100cc, ironically when you need it most.
CNG/LPG Kits come in two basic ‘varieties’ - the ‘RTO Approved’ ones and others that’re not.
The former are obviously more expensive but make your conversion ’street-legal’, enabling you to draw your supplies from the respective Road-side Retail Outlets. Retrofitters of such Kits are obliged to give you a Certificate stating their RTO Approval particulars as well as those of your Car - such as its Regn and engine/chassis #s.
Such a Certificate will enable you to seek endorsement on your RC from the concerned RTO for ‘dual-fuel’ - a responsibility you must put on the Retrofitter before you pay him up fully. However, prior to that, you will have to apply to your Insurance Co. by paying the additional premium towards the cost of the kit for your existing Policy to be so endorsed. Only then you will be fully/legally ‘operational’.
Please also ensure that your Kit is complete with the ‘Electronic/Automatic Ignition Timing Controller’ - w/o which you’ll not get the best engine performance either in Gas or Petrol Modes. Most Buyers overlook this finer aspect and the Kit-suppliers make more money by holding back on it. This is required even for the pre-2000/Carburettor type of cars. Incidentally, they’re best suited for such conversions!
There are some ‘RTO Certified’ Gas kits suitable for Mpfi’s in the market now but NOT for all the makes/models on the roads these days. Such Kits are more expensive by Rs: 5-10k compared to carb types as these have to actively interface with the Car’s main ECU and that doesn’t come cheap. This is achieved by additional features such as - a) Emulator, b) ‘Lambda’ Sensor and c) Microprocessor based Ignition Timing Controller, for ‘Distributorless’ Ignition systems that most cars have today.
Such a Certificate will enable you to seek endorsement on your RC from the concerned RTO for ‘dual-fuel’ - a responsibility you must put on the Retrofitter before you pay him up fully. However, prior to that, you will have to apply to your Insurance Co. by paying the additional premium towards the cost of the kit for your existing Policy to be so endorsed. Only then you will be fully/legally ‘operational’.
Please also ensure that your Kit is complete with the ‘Electronic/Automatic Ignition Timing Controller’ - w/o which you’ll not get the best engine performance either in Gas or Petrol Modes. Most Buyers overlook this finer aspect and the Kit-suppliers make more money by holding back on it. This is required even for the pre-2000/Carburettor type of cars. Incidentally, they’re best suited for such conversions!
There are some ‘RTO Certified’ Gas kits suitable for Mpfi’s in the market now but NOT for all the makes/models on the roads these days. Such Kits are more expensive by Rs: 5-10k compared to carb types as these have to actively interface with the Car’s main ECU and that doesn’t come cheap. This is achieved by additional features such as - a) Emulator, b) ‘Lambda’ Sensor and c) Microprocessor based Ignition Timing Controller, for ‘Distributorless’ Ignition systems that most cars have today.
While choosing a Gas Kit for an Mpfi, it’s of utmost importance that one demands to see the certified true copy of the RTO Approval that a Kit Vendor claims to have, to verify that the Kit being offered is infact suitable for his vehicle’s Make AND model. For example, a Kit suitable for Ikon-1.3 won’t be suitable for an Ikon-1.6.
In addition, one should also make sure that the ‘Bill of Materials’ as stated in the RTO-A is infact being installed in toto. But for these finer nuances, one stands to buy more trouble than intended relief and when that happens, which is generally the case with Mpfi’s, neither your Car Dealer nor the Kit Supplier will be able to help you as both will keep passing the buck to the other.
To double check, seek your Car Dealer’s advice also whether he has any Kit to recommend or install w/o affecting the Car’s warranty - even if it’s out of it.
Source:
A ‘Street-Legal’ LPG Kit for an Mpfi Car will cost you ~ Rs: 35k and ~ 25k for a Carb type. An equivalent CNG Kit may cost ~ Rs: 5k more, coz of the more expensive Cylinder. So one must do one’s cost/benefit analysis first - on the basis of, say, a pay back period of one year. Running your Car on ‘Domestic’ LPG Cylinders is not only illegal but also extremely dangerous.
As a thumb rule, one stands to save about 45% of petrol bill costs with LPG and 65% with CNG. At the same time, one stands to lose about 10% of the engine power also, due to gaseous nature of these fuels and this can cause problems with AC running during peak of summers on cars smaller than 1100cc, ironically when you need it most.
CNG/LPG Kits come in two basic ‘varieties’ - the ‘RTO Approved’ ones and others that’re not.
The former are obviously more expensive but make your conversion ’street-legal’, enabling you to draw your supplies from the respective Road-side Retail Outlets. Retrofitters of such Kits are obliged to give you a Certificate stating their RTO Approval particulars as well as those of your Car - such as its Regn and engine/chassis #s.
Such a Certificate will enable you to seek endorsement on your RC from the concerned RTO for ‘dual-fuel’ - a responsibility you must put on the Retrofitter before you pay him up fully. However, prior to that, you will have to apply to your Insurance Co. by paying the additional premium towards the cost of the kit for your existing Policy to be so endorsed. Only then you will be fully/legally ‘operational’.
Please also ensure that your Kit is complete with the ‘Electronic/Automatic Ignition Timing Controller’ - w/o which you’ll not get the best engine performance either in Gas or Petrol Modes. Most Buyers overlook this finer aspect and the Kit-suppliers make more money by holding back on it. This is required even for the pre-2000/Carburettor type of cars. Incidentally, they’re best suited for such conversions!
There are some ‘RTO Certified’ Gas kits suitable for Mpfi’s in the market now but NOT for all the makes/models on the roads these days. Such Kits are more expensive by Rs: 5-10k compared to carb types as these have to actively interface with the Car’s main ECU and that doesn’t come cheap. This is achieved by additional features such as - a) Emulator, b) ‘Lambda’ Sensor and c) Microprocessor based Ignition Timing Controller, for ‘Distributorless’ Ignition systems that most cars have today.
Such a Certificate will enable you to seek endorsement on your RC from the concerned RTO for ‘dual-fuel’ - a responsibility you must put on the Retrofitter before you pay him up fully. However, prior to that, you will have to apply to your Insurance Co. by paying the additional premium towards the cost of the kit for your existing Policy to be so endorsed. Only then you will be fully/legally ‘operational’.
Please also ensure that your Kit is complete with the ‘Electronic/Automatic Ignition Timing Controller’ - w/o which you’ll not get the best engine performance either in Gas or Petrol Modes. Most Buyers overlook this finer aspect and the Kit-suppliers make more money by holding back on it. This is required even for the pre-2000/Carburettor type of cars. Incidentally, they’re best suited for such conversions!
There are some ‘RTO Certified’ Gas kits suitable for Mpfi’s in the market now but NOT for all the makes/models on the roads these days. Such Kits are more expensive by Rs: 5-10k compared to carb types as these have to actively interface with the Car’s main ECU and that doesn’t come cheap. This is achieved by additional features such as - a) Emulator, b) ‘Lambda’ Sensor and c) Microprocessor based Ignition Timing Controller, for ‘Distributorless’ Ignition systems that most cars have today.
While choosing a Gas Kit for an Mpfi, it’s of utmost importance that one demands to see the certified true copy of the RTO Approval that a Kit Vendor claims to have, to verify that the Kit being offered is infact suitable for his vehicle’s Make AND model. For example, a Kit suitable for Ikon-1.3 won’t be suitable for an Ikon-1.6.
In addition, one should also make sure that the ‘Bill of Materials’ as stated in the RTO-A is infact being installed in toto. But for these finer nuances, one stands to buy more trouble than intended relief and when that happens, which is generally the case with Mpfi’s, neither your Car Dealer nor the Kit Supplier will be able to help you as both will keep passing the buck to the other.
To double check, seek your Car Dealer’s advice also whether he has any Kit to recommend or install w/o affecting the Car’s warranty - even if it’s out of it.
Source:
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