I have ordered a copy of a supplement to the 1992 factory service manual titled: Compressed Natural Gas-Ram Van/Wagon-Rear wheel Drive. Has anyone seen or own a vehicle from that era equipped from the factory with CNG? Thanks

 

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Thanks for the reply. I am starting to see that this is just not going to work in Maine. The road tax alone in Maine is just ridiculous and I have no well to get the fuel for free. Gasoline it is.

 

No problem.

A lot of things that sound good on paper simply don't translate to practical application except in very specific circumstances.

 

Hi,
I have to disagree:
Using Propane, you get almost the same horsepower with a venturi (mixer) style LPG system (which is used on carb or TBI engines) and about 10-30% more consumption (in liters or gallons, not weight!). Using a sequential vapor propane injection, as on most conversions on modern cars with multipoint injection, you get no power loss at all, and about 10-15% more consumption. And using a liquid propane injection (I only know about 2 manufacturers here in Europe), you get even MORE power than on gasoline.
In all cases, if the engine is tuned to the propane (spark advance, compression ratio! Because LPG has a much higher octane rating!), you get more power than on regular gasoline.
Propane consumption is a bit higher, 10-15% is the theoretical value, that's what it has less potential energy per volume. But here in Europe, you pay less than half of the gasoline price (right now, Germany: LPG 0,50€ per Liter, 98 octane gasoline 1,37€ per liter), so you end up paying only 50%! That's the only way driving old American V8's over here

On CNG, which is sold by weight over here, the consumption is about half (so if the vehicle used 10 liters gasoline, it will use 5kg CNG), which also adds up to half the price, because the cost per kg is only a bit less than per liter of gasoline.
I don't know about power loss or gain, CNG is not very common over here. If any, then you get it straight from the car manufacturer. Conversions are not common, only LPG.

So long,
Daniel

 

Where is "over here"?

 

Since he's quoting prices in Germany I would say it's a safe assumption that's where is he.

 

Oh, yes
What are the prices in the US? Does it make (financial) sense to convert cars to LPG or CNG "over there"?
I know your fuel prices went up a lot since I've been there in 2000, I got the gallon for about 1.3$ that time... but still, your fuel prices are like paradise for us, we've been as high as 1.80€ per liter, that's more than 7$ per gallon...

 

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So, it's useless in the US for savings reason...

BUT, you can trust me, I have 3 LPG cars and a friend of mine has 5 (yes, really, he's a freak ;-) ) and another friend of both of us runs a LPG conversion company:
You have NO power loss using LPG, all our cars still run their top speed (or more) on LPG as on gasoline.
All you have is a slightly higher consumption, which in real world is around 15-20%.

You should read the wikipedia page, not just link it... it says LPG has 74% energy... and this is for "your" LPG, which seems to be pure propane. In Europe, we use 60/40 Butane/Propane in summer, 40/60 in winter. That gives a bit more energy, so my initial statement is correct.
The maximum consumption is 26% higher according to the wiki list.

And why should you get less power? You simply inject more LPG than gasoline, that's all! Or would you say, a methanol dragster has less HP... no, they just put a lot more fuel!
That's why you have more fuel consumption using E85 or whatever ethanol mixture... but not less power.

Btw: Most modern engines are programmed to "scan" for the maximum spark advance, they run at the knock-limit, so they can take advantage of "better" fuel. Especially the multifuel (ethanol mix) engines in the US should be able to to that. Probably not to the 100something octane of LPG...

Now, let's stop here... the question actually was, whether someone has seen an original CNG van...