Gas consumption/Km

More than 3.5l/km, as CNG is a gas.

Assuming that your tank will be filled with CNG under pressure of 3000psi/g, your fuel consumption will drop down to around 3 lt per km

BTW, do u actually mean 3.5 km per lt?

because @ 3.5 lt per km you have a seriuos fuel guzzler
CNG increases the mileage of the vehicle to some extent, but the BIGGEST thing that goes in favour of CNG is that 1 kg of CNG costs around half of that of 1 kg of Pertrol
besides it being environmentally friendly fuel

Converting a diesel engine to running on gas is an expensive business, you would be better off starting with a petrol engine for such a conversion I feel.

Was your fuel consumption as high as you made it to be, that is:- 350 liters per 100 kilometers????

@Andy Germany
Retrofitting a Diesel engine to use CNG may be expensive in terms of initial investment, but he should be able to recover his investment through reduced running cost

You don't really suggest that he buy a petrol vehicle just to retro-fit it, do you :-) ?

Because the impression that his post gave me was that he is the owner of a Diesel run vehicle and wants to retro-fit it to run on CNG

I sincerely believe that the changes needed to convert a Diesel engine probably out weigh the cost of a petrol engine. I could be wrong, but somewhere I have read that if you want to burn gas, you don't start with a diesel.

I would most appreciate being told of a web site or similar where such conversions are made (Diesel to Gas), not that I want to do it, I am just technically nosey and wanting to learn something new.....

But even if the conversion is made, you have an engine that is also physically much heavier than a similar sized petrol engine, lugging around extra weight is not good for consumption either.

A petrol engine basically only needs relatively minimal additions/changes to burn gas (which is what it does already if you live in the USA!!).....

I am very interested in what happens in this blog and with the diesel consumption (assuming no errors) claimed, he will need to do something pretty quick!

AFAIK all buses (diesel-run) in India have been converted to run on CNG. Although, cutting down emissions from the vehicles was the sole reason behind such a move. But, I guess this move has been economically feasible too, else, I dont really see them going for this if it put additional burden on their exchequer
You could also contact some CNG conversion kit dealer/mfg in Germany
Found a few Intl dealers online, but not sure if they would entertain queries from some guy living in a different country, esp, if they do not conduct business there
the google code that I used was
"CNG conversion kits" (quotes included)
You might want to use
"CNG conversion kits" +Germany (quotes included)
I agree that the percentage of weight added to a retro-fitted car would be a lot more than if it it is attached to a Bus (as is the case in India)
But I guess that if the vechicle consumes 3.5 lt for 1 KM, it ain't going to be a Sedan :D

Here in Australia we get money back from the government for a conversion from petrol or diesel to LPG GAS. I assume that is the same thing as CNG?

http://www.ausindustry.gov.au/content/level3index.cfm?ObjectID=D47685C8-0B0B-459C-B07A2EFBDB3D4AF7

Really interesting to read about, but at least part of my critic would appear to be right:-

Hybrid's Fuel 2 kit allows the diesel engine to run on either compressed or liquefied natural gas. The Fuel 2 kit retails for $4,500. Fuel storage tanks, catalyst and linkage will bump the total cost per conversion up to around $10,000.

This shows that the costs of conversion are not dissimilar to a new petrol engine and the parts needed to use gas!

The main usage would appear to be when buses for example need to be run as dual fuel, that is either gas or Diesel....

Furthermore, the development time and costs needed are extreme (as explained in the other link kindly supplied), it is not something an individual will do for one vehicle I feel, or only an extremist maybe with more money than sense.....

BUT it does show that this is possible, many thanks for the infos!

If your fuel consumption is that high you should consider a bicycle.