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: