Running on Propane - LPG ????

Need advise on running propane in my yukon..

I have a 01 Yukon 5.3l and it has a propane conversion kit on it. The guy I bought it from never used it and I have been running on GAS all this time.
I wanted to get opinions/advise on using Propane in my yukon as below:
1. Is it really cost effective?
2. Propane in california also known as LPG costs about 3 bucks a gallon. What kind of mileage can I expect running on propane. Is it higher or no differnet than gas?
3. How do you switch between GAS and Propane? Is there supposed to be a switch to engage propane instead of regular GAS??

Appreciate any help you can provide..

P.S. I have no idea what kind of conversion kit it is and can't find any information on what the conversion entailed. I showed it to my mechnaic and he looked at it and said that it looks like all the systems are hooked up and he can't find anything that is disconnected.

Need advise on running propane in my yukon..

I have a 01 Yukon 5.3l and it has a propane conversion kit on it. The guy I bought it from never used it and I have been running on GAS all this time.
I wanted to get opinions/advise on using Propane in my yukon as below:
1. Is it really cost effective?
2. Propane in california also known as LPG costs about 3 bucks a gallon. What kind of mileage can I expect running on propane. Is it higher or no differnet than gas?
3. How do you switch between GAS and Propane? Is there supposed to be a switch to engage propane instead of regular GAS??

Appreciate any help you can provide..

P.S. I have no idea what kind of conversion kit it is and can't find any information on what the conversion entailed. I showed it to my mechnaic and he looked at it and said that it looks like all the systems are hooked up and he can't find anything that is disconnected.




This is what these guys think...It sounds like e85 comparison.

http://www.tundrasolutions.com/forums/engine-and-drivetrain/44423-tundra-cng-or-lpg-conversion/

I have a 5.3 Yukon XL. I have tried E85 several times. I normaly buy it when its more than 10% cheaper than gas (to cover for the loss of mpg).
I tow 7800 lbs every other weekend with it. I found have more power with a mixture of the two fuels. I think it because of the high octane (105) of the E85 (more total advancement). Why not add some LP and try it? I would check the cost of a gal. of it. Most truckstops or camping places sale it per gal vs a pound so it would be easy to buy it.