CNG fueled Elise

[andytk]

Check this out.
Could this be the answer to chronicly overtaxed petrol?

www.indiacar.com/infobank/ntech_cng.htm

www.planetark.org/dailynewsstory.cfm/newsid/7514/newsDate/19-Jul-2000/story.htm

www.sandsmuseum.com/cars/elise/press/press/press2001/gasfeed.html

The three stories are all about the same car but all have slightly different slants.

Its does look like a great idea though. Like ethanol and LPG the octane rating is over 100 so if you had a dedicated CNG engine you would be able to tune it for efficiency or power

The biggest advantage is that cos its drawn from a domestic supply the government can't simply whack a great big tax on it without causing mass riots. Also its a "clean" fuel so the govenment have pledged not to tax the life out of it (just yet ).

Plus I wouldn't say no to a Lotus Elise.

Andy

[andytk]

Just out of curiosity how much is domestic gas these days? Preferably in cost per cubic meter at STP. I heard that it was about 1.5p per KWh but I don't know how much gas constitutes a KWh.

Cheers

Andy

[gtir]

I am pretty sure that like LPG, CNG has a lower "power" ratio than petrol. Thats why you get less MPG than you would with petrol.

I am all for alternative fuels mind you, but CNG and LPG are all finite resources , blah blah blah.

[andytk]

gtir said: I am pretty sure that like LPG, CNG has a lower "power" ratio than petrol. Thats why you get less MPG than you would with petrol.

Its not so much power but energy density. Ie. you need more space to store it than petrol. Power obtainable is all about engine design and octane rating though. With higher compression ratios though you do get better thermal efficency. Which means that in purely thermal energy terms an LPG or CNG dedicated engine should be more environmentally friendly cos they'd emit less CO2 emissions,

Not that I give a stuff though. The car I want happens to be a TVR Chimeara.....

All I want is cheap fuel and to stop funding govenmental stupididy through fuel tax.

Andy

[Byff]

I've got the running costs etc of LPG here:

www.pistonheads.com/gassing/topic.asp?f=23&t=28138&h=0&p=

I'd like to know if there is any difference between LPG and CNG. It may be possible to connect a hose, pressure regulator and nozzel to your gas supply.

[andytk]

Um bearing in mind that CNG (=domestic gas) is completely different from LPG.

You need a different tank and different regulator. IIRC LPG is pressurised to 10bar and CNG to 200bar. BIG difference. The CNG tank is more like a scuba tank. Whereas the LPG tank is more like a camping gas bottle.
It would be interesting to see the running costs on CNG. Acording to one of the articles a 40litre tank at 200bar carries as much energy as a 10 litre tank of petrol.
Wonder how much it would cost for the gas to fill a 40litre tank to 200bar?

Andy

edited cos I'm suffering from brain fade

>> Edited by andytk on Monday 3rd February 19:31

[Byff]

andytk said: Um bearing in mind that CNG (=domestic gas) is completely different from LPG.

You need a different tank and different regulator. IIRC LPG is pressurised to 10bar and CNG to 200bar. BIG difference. The CNG tank is more like a scuba tank. Whereas the LPG tank is more like a camping gas bottle.
It would be interesting to see the running costs on CNG. Acording to one of the articles a 40litre tank at 200bar carries as much energy as a 10 litre tank of petrol.
Wonder how much it would cost for the gas to fill a 40litre tank to 200bar?

Andy

edited cos I'm suffering from brain fade

>> Edited by andytk on Monday 3rd February 19:31

Thats got me thinking. I wonder how much it is to fill a 20kg bottle of camping style calor gas. It could be cheaper to chuck one of those in the boot.

[andytk]

Byff said:
Thats got me thinking. I wonder how much it is to fill a 20kg bottle of camping style calor gas. It could be cheaper to chuck one of those in the boot.

There are two types of camping gas. Butane and Propane. LPG is basically a mix of these two gasses so to all intents and purposes its the same stuff.
The only problem is a 20kg propane tank you'd buy for camping won't meet all the car type crash regulations that LPG conversion tanks have to. So in a crash there could be a very big bang.
Although the price difference between taxed LPG from a gargage and the untaxed Propane from a camping gas cylinder would be intersting. Could you simply decant a big ol camping gas tank into the gas tank in your (converted) car and dodge the tax? Hmmmm

Andy

[Byff]

andytk said:

the price difference between taxed LPG from a gargage and the untaxed Propane from a camping gas cylinder would be intersting. Could you simply decant a big ol camping gas tank into the gas tank in your (converted) car and dodge the tax? Hmmmm

Andy

That's what I was wondering. Probably only need a pump to provide the pressure to force it in, but this sucker aint going to be the first to try it.