CNG or propane conversion

[superu]

I have been thinking of doing a conversion to my 95 legacy 2.2. It'd be nice to burn cleaner than gasoline, especially with raising fuel costs. Plus it would be cool to be able to use the car pool lane with the incintive or a cleaner-burning automobile...

 

I would like to be able to run gasoline also and I understand when doing a propane conversion you can switch and run either gasoline or propane. is the same true for CNG?

 

So I've mainly thought about propane, but recently i've thought about CNG as well.

 

Does anyone know good pros and cons of each of these and how it could be done?

 

thanx,

-mw-

[LPGsuperchargedBrumby]

i run LPG (propane) and wouldn't switch back

 

PRO'S:

cleaner running

oil doesnt get dirty like on liquid fuel

high octane fuel

Being a hippy motorhead

 

CON'S:

less MPG on propane

tank has to be mounted somewhere

finding room under bonnet to mount vapouriser

can give problems in cold areas

 

you can run dual fuel and on a fuel injected motor it shouldn't hurt you MPG on petrol or propane (converting a carb'd motor to dual fuel reduces your MPG because of the extra ventury of the propane ring)

 

there is also propane injection systems available that duplicate your petrol injection system in operation and run a piggyback drive off your ECU....

 

i haven't had alot to do with these but know that the cold area problems are more of an issue as they need a propane pressure about 30psi higher that manifold pressure...and the colder the tank is the less pressure there in it...however i have seen a tank designed for use in canada(i think) that had a fuel pump in the tank to boost pressure in the cold

[cubastreet]

You won't get many miles out of a tank of cng, propane is much better in that respect.