CNG Talk

[g8crasher]

Since CNG is all the rage now, I think it's a real interesting debate as to whether it's a viable enough solution! I think alot of us here are aware CNG conversions will incur a loss of power. Hey I'd whole heartedly agree especially if you use a conventional, heavy & ugly looking CNG tank. Not only will this take up boot space, it might actually cause premature spring sagging with all that permanent weight sitting on top of your rear suspension system! *it's not proven, just a logical theory*

For all you environmentalist minded folks out there that only want the goodness CNG can bring to the wallet, this may be a must have tank from Faber Italy - LIGHTWEIGHT CNG tanks made from Steel and fibre. No prices indicated so you might want to send them an email to inquire. http://www.faber-italy.com/light/fra.htm

Wouldn't it be nice to have a carbon fibre CNG tank in the boot instead ? :thumbsup:

For further information on CNG in Singapore, please refer to www.cng.com.sg

For a more scientific explanation on CNG vs conventional fuel, please refer to http://www.naftc.wvu.edu/NAFTC/data/indepth/LPG/LPG.html

[g8crasher]

Description

This article is from the Gasoline FAQ, by Bruce Hamilton with numerous contributions by others.

9.4 Why are CNG and LPG considered "cleaner" fuels.

CNG ( Compressed Natural Gas ) is usually around 70-90% methane with 10-20%

ethane, 2-8% propanes, and decreasing quantities of the higher HCs up to

butane. The fuel has a high octane and usually only trace quantities of

unsaturates. The emissions from CNG have lower concentrations of the

hydrocarbons responsible for photochemical smog, reduced CO, SOx, and NOx,

and the lean misfire limit is extended [117]. There are no technical

disadvantages, providing the installation is performed correctly. The major

disadvantage of compressed gas is the reduced range. Vehicles may have

between one to three cylinders ( 25 MPa, 90-120 litre capacity), and they

usually represent about 50% of the gasoline range. As natural gas pipelines

do not go everywhere, most conversions are dual-fuel with gasoline. The

ignition timing and stoichiometry are significantly different, but good

conversions will provide about 85% of the gasoline power over the full

operating range, with easy switching between the two fuels [118]. Concerns

about the safety of CNG have proved to be unfounded [119,120].

CNG has been extensively used in Italy and New Zealand ( NZ had 130,000

dual-fuelled vehicles with 380 refuelling stations in 1987 ). The conversion

costs are usually around US$1000, so the economics are very dependent on the

natural gas price. The typical 15% power loss means that driveability of

retrofitted CNG-fuelled vehicles is easily impaired, consequently it is not

recommended for vehicles of less than 1.5l engine capacity, or retrofitted

onto engine/vehicle combinations that have marginal driveability on gasoline.

The low price of crude oil, along with installation and ongoing CNG

tank-testing costs, have reduced the number of CNG vehicles in NZ. The US

CNG fleet continues to increase in size ( 60,000 in 1994 ).

LPG ( Liquified Petroleum Gas ) is predominantly propane with iso-butane

and n-butane. It has one major advantage over CNG, the tanks do not have

to be high pressure, and the fuel is stored as a liquid. The fuel offers

most of the environmental benefits of CNG, including high octane.

Approximately 20-25% more fuel is required, unless the engine is optimised

( CR 12:1 ) for LPG, in which case there is no decrease in power or increase

in fuel consumption [27,118]. There have been several studies that have

compared the relative advantages of CNG and LPG, and often LPG has been

found to be a more suitable transportation fuel [118,120].

methane propane iso-octane

RON 120 112 100

MON 120 97 100

Heat of Vaporisation (MJ/kg) 0.5094 0.4253 0.2712

Net Heating Value (MJ/kg) 50.0 46.2 44.2

Vapour Pressure @ 38C ( kPa ) - - 11.8

Flame Temperature ( C ) 1950 1925 1980

Stoich. Flame Speed. ( m/s ) 0.45 0.45 0.31

Minimum Ignition Energy ( mJ ) 0.30 0.26 -

Lower Flammable Limit ( vol% ) 5.0 2.1 0.95

Upper Flammable Limit ( vol% ) 15.0 9.5 6.0

Autoignition Temperature ( C ) 540 - 630 450 415

[Guest eyke]

or buy purpose-built E200 NGT which doesn't suffer loss of power...

[g8crasher]

or buy purpose-built E200 NGT which doesn't suffer loss of power...

Hahahahahaha :thumbsup:

[keltanky]

or buy purpose-built E200 NGT which doesn't suffer loss of power...

C&C will bring the low selling NGT anymore meh? And i remembered that the this NGT don't qualify for the green tax! As its gas tank is not more than 50 litres!

[Guest eyke]

C&C will bring the low selling NGT anymore meh?

yup, should start arriving from Sept, in Elegance trim.

price is -$10K from E200K price.

[g8crasher]

After CNG conversion, 15% power loss plus additional weight of the CNG tank in the boot = 0-100 8 seconds leow

I m not aware if CNG is readily avail across the causeway in petrol stations ?

[keltanky]

only 2 stations have CNG in JB as of now!!

in KL and Northern side have loads of them!!

[Guest jenvid]

g8crasher ]

Wouldn' wrote:

And have a potential claymore mine shld the thingy explode ? You been mixing with Al Qaeda folks lately ? ;D ;D ;D

keltanky ]

or buy purpose-built E200 NGT which doesn' wrote:

C&C will bring the low selling NGT anymore meh? And i remembered that the this NGT don't qualify for the green tax! As its gas tank is not more than 50 litres!

I thot it did.... else how to be cheaper ?

[g8crasher]

And have a potential claymore mine shld the thingy explode ? You been mixing with Al Qaeda folks lately ?

On the bright side, one will die faster via carbon fibre shard poisoning :thumbsup:

[Guest sy69u]

only 2 stations have CNG in JB as of now!!

in KL and Northern side have loads of them!!

yes, saw 1 of the stations on the way to tanjong putri. mostly taxis filling up. the line was like a scene at the woodlands causeway on a public holiday.