CNG anyone?
CNG (compressed natural gas) is quietly being used by a lot of councils for their vehicles, but not really pushed as a consumer product.
A lot cheaper than LPG, easy fill from home gas supply, seems a no brainer.
Anyone had it done or has a CNG vehicle?
What is it like?
Involved with many of those councils running many Econic CNG bin wagons
Great pieces of kit, a few Sprinters too and all good reports...
Not heard too much outside of that....
As for a comparison between LPG / CNG then literally are the chalk and cheese
LPG is in the main a tedious and poor substitute in my view, especially on vehicles 15 years or never...
CNG seems to be seamless but a different animal...
LPG + PETROL ENGINE = HEAT
CNG + DIESEL ENGINE = ECONOMY
CNG + PETROL ENGINE = ??? I HAVE HAD NO CONTACT
Just my findings...
much the same as this http://www.lowtechmagazine.com/2011/11/gas-bag-vehicles.html
CNG essentially methane CH4 has a much lower calorific and hence octane rating than LPG and is problematic for cars. Methane, Ethane, Propane, Butane, where LPG is a blend of the last two gases in the sequence, and the octane rating is similar or higher than for petrol. In short you will need more CNG to achieve the same result so you need to store more gas at a higher pressure to achieve similar results. You also need the filling stations to supply the gas. So stronger bigger and heavier tanks required and a network of supply, potentially a useful alternative to petrol but more work needed.
A lot cheaper than LPG, easy fill from home gas supply, seems a no brainer.
I don't think that you would be able to travel very far if you tried to fill your tank from your domestic gas supply.
To convert natural gas into CNG it is compressed to 3000psi which allows it to be stored in your fuel tank in sufficient volume to get beyond the end of your driveway.
Natural gas has a domestic pressure entering the home of around 1psi and so without the aid of a compressor you are not going to get very much stored in your tank. It would take roughly 140 cubic feet of gas at atmospheric pressure to equate to 1 gallon of diesel.
The problem with the HomeFill type units is that it still takes around 10 hours to fill the car for around a 200 mile range.
You would need a bulk storage tank and a big compressor to be able to refuel in a similar time to a petrol station with CNG.
And despite the protestations of safety a gas that has the ability to expand 2 or 3,000 times has enormous explosive potential. The gas pipe line from Milford to England is liquefied at 96 atmospheres which a 14 per sq inch for one is 1344 psi. Scary stuff and as most CNG is from gas fields or as a oil product it is not in the least bit environmentally friendly
Thanks Gav,
Useful to know.
Seems the sprinter ones are dual fuel petrol ones and the new name is now NGT, but still the same thing.
http://www.mercedes-benz.com.au/content/australia/mpc/mpc_australia__website/en/home_mpc/van/home/new_vans/models/sprinter_906/sprinter_ngt.html