NG Vs LPG - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 03-19-03, 07:27 PM Thread Starter
P1mp Daddy
bigred's Avatar
Join Date: Oct 2001
Location: Melbourne
Posts: 518


Is Natural gas, that heats my water and cooks my noodles, basically the same stuff that LPG is made out of ?

Because if it could run your car...
Natural gas costs SFA!


bigred is offline  
Sponsored Links
post #2 of 5 (permalink) Old 03-19-03, 08:22 PM
Oxford Green AU
AUForte's Avatar
Join Date: Oct 2002
Location: Melbourne, Victoria
Posts: 1,281
No it's not, there are however CNG (Compressed Natural Gas) converted cars out there.

From memory there's about 195 CNG filling stations in Aust, althogh they're mostly fleets and taxis due to the expensive pump required to fill cars. From memory there's about 195 CNG filling stations in Aust.

I saw a write up on a CNG falcon, it had 3 tanks and stiffened rear suspension for the weight and still didn't get amazing distance although the emissions were next to nothing and as you said the cost of the gas is SFA so very economical if the cost of the filling station is spread across many vehicles.

Dual Fuel 10/98 AU1 Forte
AUForte is offline  
post #3 of 5 (permalink) Old 03-19-03, 10:02 PM
A Ford Guy
Jimbo's Avatar
Join Date: Jun 2001
Location: Lara, Australia
Age: 47
Posts: 68

No Natual Gas and LPG (liquified petroleum gas) are quite different.

Natural gas is usually stored as Compressed Natural Gas (CNG) on a vehicle and is mostly methane (95%+). CNG is still a gas at the high pressures (20 MPa/3000 psi) that the tanks get filled to. Because of this high pressure the tanks are thick steel (expensive and heavy) or a composite (very expensive but lighter). A conversion kit to fit CNG to a car looks similar in principle to an LPG kit but all the components on the high pressure side, such as the tank, fuel lines, and regulator are very different. In Australia there are only about 2 or 3 public refuelling stations, with most of the other refuelling facilities catering for captive fleets such as forklifts and buses. Natural Gas can be liquified, but only at very low temperatures, about -162C. The storage containers in vehicles for LNG are complex cryogenic containers. LNG is the way natural gas is shipped to Japan and China from off the North West Shelf. LNG plants are big and expensive and need to produce heaps of LNG to be economically viable.

LPG is a mixture of propane and butane (with such other stuff occasionally thrown in). The actual ratio of the two varies depending on where it was sourced from. LPG liquifies under pressure, hence its name, and therefore is stored on the vehicle as a liquid and usually converted to a vapour before being mixed with the intake air to supply the engine. Australia has heaps (about 3000 or more I think) refuelling stations around Australia.

Because LPG is a liquid you can store a lot more of it in a tank than you can with CNG for the same volume. A 90 litre tank on an LPG Falcon would get you about 600 - 700 km whereas a 90 litre CNG Falcon would get about 150 - 220 km.

CNG does have some advantages though. Usually it is cheaper than the other fuels (per kJ) and its price is very stable, about as stable as your household price for gas. There are also some companies developing vehicle refuelling appliances for the home. These are small compressors that take the gas from the household and compress it into the car, the only problem with this is it takes about 8 hours to refuel. Public CNG refuelling stations store high pressure gas on site (at 25 MPa / 3600 psi) and can fill a car in a few minutes. CNG also has the potential to have fewer emissions than LPG or petrol and also produce less CO2 emissions, but like all things the engine has to be optimised to take full advantage of the properties of CNG. The most obvious difference is the octane rating, methane has an octane rating of about 135 - 140 (if the scale could go that high) and as such the compression ratio can be increased dramatically.


The ships hung in the air in exactly the same way that bricks don't...
Jimbo is offline  
post #4 of 5 (permalink) Old 03-19-03, 10:05 PM
Registered User
Falchoon's Avatar
Join Date: May 2001
Location: Somewhere over the rainbow
Posts: 3,544
I think there were plans with the CNG to be able to fill up at home but I think it was knocked on the head because the Govt wouldn't get their cut (tax) if people did that. There might be some safety concerns too. I think too the range on CNG is quite limited, like only a couple of hundred kms to a regular size (whatever that is) tank in a 6 cyl Falc or Commie.

You know, somebody actually complimented me on my driving today. They left a little note on the windscreen. It said, 'Parking Fine.'So that was nice.

Falchoon is offline  
post #5 of 5 (permalink) Old 03-20-03, 03:18 PM
Join Date: Oct 2002
Location: Melbourne
Posts: 290
I think that falcon that is spoken off with the 3x gas tanks had a compression ratio of like 13.5:1 or along those lines somewhere..
headsex is offline  
Sponsored Links

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > LPG Tech

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome