The Big Fight: CNG v/s LPG


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Here are few interesting facts that i found on net!

Advantage of Using CNG Fuels! Compressed Natural Gas (CNG) is a substitute for gasoline (petrol) or diesel fuel. It is considered to be an environmentally "clean" alternative to those fuels. It is made by compressing methane (CH4) extracted from natural gas. It is stored and distributed in hard containers, usually cylinders.

Green fuel -
Commonly referred to as the green fuel because of its lead and sulphur free character, CNG reduces harmful emissions. Being non-corrosive, it enhances the longevity of spark plugs. Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs, and lead or benzene pollution are eliminated.

Increased life of oils - Another practical advantage observed is the increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil.

Mixes evenly in air - Being a gaseous fuel CNG mixes in the air easily and evenly.

Advantage of Using LPG Fuels! Liquefied petroleum gas (LPG) is mostly propane when used for automotive purposes. It is produced as a by-product of natural gas processing or oil refining, and is often used as a bottled gas for cooking and heating. LPG is mainly used in cars and light vans. This means they have separate tanks for the LPG and petrol, and can operate on either fuel simply by flicking a switch. Running solely on LPG will however provide the greatest environmental and financial benefits although a small amount of petrol will be needed as most LPG vehicles start up on petrol and then switch over to LPG after a few seconds. In India the supply is as per BIS : 14861

Perceived advantages :-
1) Kit costs as low as Rs.6000/- to Rs.7000/- (CNG kits cost upwards of Rs.30,000/-)
2) Cost per kilometer of running approx. 80 paise (petrol being nearly Rs.2 per km)
3) Household subsidised cooking gas cylinders available easily.
4) Dealers available dime a dozen in every locality who proclaim their ongoing illegal business of fitting LPG kits in vehicles as legal.

Advantages over other fuels
The combustion of Autogas is smoother as a result of the higher octane content. Unlike other fuels, no additives are required to guarantee high quality.
• Autogas contains no lead and is therefore cleaner and leaves no residue.
• It is actually better than petrol because it reaches the engine in pure gas form with improved combustion resulting and fewer knocking.
• With modern technology, there is hardly any discharge of carbon monoxide, and compared to petrol and diesel, the exhaust fumes contain less harmful substances.
• The life of the engine is extended as a result of the absence of acids and carbon deposits. One can safely state that engines on LPG last almost twice than that on Petrol/Gasoline.
• Less carbon means less fouling of spark plugs and points i.e less wear and tear.
• The engine oil does not become diluted with a consequential reduction in servicing costs.
• Unlike diesel, you do not have to adjust your driving style. Cold starting is no problem, engine performance is almost exactly the same as with petrol. There is no spilling when filling your tank and no possibility of theft or pilfering. Engine noise is low and you'll be driving in a more environment-friendly way.
• The environmental advantages of Autogas for automotive use are indisputable.

Actually there are ample amount of information available on safety cost & Environment! You can visit http://www.ecogas.co.in for more details![cheers]
 
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CNG is Diesel engine compatible & LPG is petrol engine compatible.(Mostly)

LPG can also be used in Diesel engines but then it needs to be mixed with diesel first & then injected into the engine.(This increases the cost.Its generally done in foreign countries as it gives excellent efficiency & power)

Some PLUS POINTS of CNG over LPG are -


CNG cylinders are safer than gasoline or LPG.

CNG being ligher than air, even if leaked, goes up and unlike LPG does not Spread on ground surface.

CNG is still in gaseous form and safer than liquid fuels.

CNG burns only at a specific air fuel ratio. It needs strong and high density current/energy to ignite lean mixtures.

Literally zero particulates with CNG, NOx and CO balance is sensitive to air fuel ratio.

Very less /marginal HC in emissions.
 
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Some things I know about CNG. Not in any sequence of importance or anything.
One. as mentioned, it is available in only a few cities, Delhi, Mumbai, and Cal, I know for sure. I think Jaipur too.
Two. CNG kits are much costlier than LPG kits. this is mainly coz the pressures inside the CNG tank are much higher, about 60 atm. is what I remember.
Three. You can always get a full tank of LPG when you go filling. In CNG, the amount (in Kg) that you can fill of the tank depends on the pressure available at the filling station, lower the pressure available, the less you can fill.
Four. CNG is dispensed in kgs, LPG in litres.
Five. A big problem with both LPG and CNG conversions is that there is a loss of power as compared to the petrol run, this is compounded in CNG coz the power will drop with falling pressures in your CNG tank, as it empties.

Will add more as and when I remember anything!!
 
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CNG vs LPG

Why opt for Gas?:
• Lowest running costs (compared to other fuel alternatives like diesel)
• Cleaner emissions
• Better resale value (in the case of factory-fitted kits only)
• Complete manufacturer-support available
• Any time switch over to petrol is possible

Factors that may hold you back:
• Initial investment in setup
• Reduced boot space
• Compromised power delivery
• Limited availability (compared to petrol and diesel). Few highways have consistent supplies. Also, some towns may not have any supply at all.
• Longer waits at the fuel pump

Are Natural Gas powered vehicles safe?

Natural Gas is an ideal fuel source for many reasons, including safety. Natural Gas is lighter than air. This means that it will not puddle (like petrol) which is heavier than air. Instead, Natural Gas will rise and dissipate in the atmosphere. Natural gas also has a higher ignition temperature. This means that it is much harder to ignite. Also the storage systems used for CNG and LPG are stronger than the petrol tanks found on cars and trucks today.

Want to switch? Here’s what you should do:
Consult the professionals at authorised high-quality service stations for the correct advice. Agreeably, this may cost you about 20% higher compared to your local unauthorised service station. But compared to the authenticity of the advice, reliability of the fittings and efficiency of the system, this price differential is well worth it.

Remember to:

• Endorse your registration certificate accordingly.
• Notify your insurance company. The premium may also go up marginally.
• If yours is a brand new car, you may stand to lose warranty coverage (even if the fitting is from an authorised service station).
 
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CNG or LPG?

Hi guys,
Bad news again. Petrol prices up[frustration]
So thought of converting my 2003 Zen mpfi to alternative fuel.
I have a few doubts though..
1)Which one is better? LPG or CNG?
2) Is it difficult to get the right tuning after switching over?
3) does the car need frequent servicing?
4) Does it affect engine life? I read somewhere the carbon deposits increase.
5) Zen is just 1000cc, will it affect the performance?
6) Any trusted installers in Pune?
Thank you..
 

johan

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I hear the cng tanks are bigger than lpg is it true?

Karthik.
Hi Karthik
Its true that CNG tanks are bigger then LPG tanks as CNG is heavier gas. One more thing CNG is safer gas and in gaseous stage. LPG is in liquid stage and turns to gaseous stage when left to atmosphere. And both are for the petrol engine.
 
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1)Which one is better? LPG or CNG?
CNG - Cost is lower than LPG, also CNG gives more mileage

CNG - 38 Rs/kg Zen gives 20km/kg in city and 28 km/kg on Highway
LPG - 43.50 Rs/kg Zen gives 15km/kg in city and 18 km/kg on Highway


2) Is it difficult to get the right tuning after switching over?
No

3) does the car need frequent servicing?
No

4) Does it affect engine life? I read somewhere the carbon deposits increase.
With LPG yes littlebit
Not with CNG

5) Zen is just 1000cc, will it affect the performance?
Yes It will affect city driving

6) Any trusted installers in Pune?
Check my thread - http://www.theautomotiveindia.com/f...55-maruti-zen-mpfi-2006-cng-installation.html
 
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