propane or CNG

[heehaw]

is anyone fueling their vehicles with propane or Compressed Natural Gas?
how does it compare to the @ $4 a gallon gas now?
heehaw

 

[jinjimbob]

I use propane for the house, propane costs around $2.80 a gallon now, but you get around 30% less energy from burning propane. If oil prices go up, propane goes up, as that is where it comes from.

Natural gas gets less energy, but it costs a lot less. I only see government cars/buses that use natural gas. I think that will change though, it will be become more widespread. . . . . but then those prices will go up anyway.

 

[heehaw]

you can "prebuy" propane around here for $1.99 right now: so for that price compared to $4 i could do with less power if i had to..but i don't know what it would take to convert a vehicle?
heehaw

 

[kenmac]

for cng (& probably propane)..You will have to purchase a conversion kit $$$$ ..then, reprogram the computer, have tanks installed have them tested every x # of years find a public fill station or, a commerical filling station that will charge for a fill.You won't loose much if any power with the right conversion kit & program

 

[jinjimbob]

I have read where people prebought a lot of propane, the prices shot up, and the supplier couldn't go through with the deal and went bust.

A natural gas civic can only go 150 miles before needing a fill up, takes 16 hours to refill it.

You might want to look into getting one of these, 2008 Honda Civic GX - the Official Honda Web Site

 

[Bird]

Of course it's been 15 years since I was doing gas leakage surveys, so I would expect considerable progress to have been made since then. However, the gas company in a major city had their pickup trucks converted to burn either gasoline or natural gas. I didn't understand just why, but at different facilities, they had different systems for refueling. At one facility, the driver could hook up the hose and refuel with CNG in about the same time it would take to refuel with gasoline, but at the other facility, each truck had its own parking space and the driver had to hook up the refueling hose when he parked and it was left hooked up overnight.

That gas company had another problem. The range on a tank of CNG was considerably shorter than for gasoline and the drivers complained of a lack of power. So the company was having a problem keeping the drivers from running on gasoline instead of CNG.

 

[chadincolo]

Running propane on an 85 3/4 ton Chevy with a dual fuel kit (pull a knob, flip a switch and it runs on gas). The people who say it's 30% less efficient are running through the stock carb. If you put a bigger carb (running an 800 cfm on a 350) you won't loose near that much mileage or power. Propane contract for next winter is 2.29, fill right now is 2.49. Next winter I'll be driving for 2.29/gallon, while gas may well be 5/gallon...even if I get 8 mpg rather than 10 mpg, I'll be saving. I do have to buy a $100 "tax sticker" for it to cover road taxes.

Yes, without changes you loose some power. Bump up your timing (can buy a kit to change it from the cab with a dial) and run an intake system that flows enough and you will be comparable on power, but for saving half the cost, I can go a little slower...

Currently pulling together parts, hopefully next spring it will be a dedicated propane (no gasoline) engine running about 8-10 pounds of boost. Propane is equivalant to 107-114 gas. Lack of power shouldn't be a problem then.

 

[charlz]

Currently pulling together parts, hopefully next spring it will be a dedicated propane (no gasoline) engine running about 8-10 pounds of boost. Propane is equivalant to 107-114 gas. Lack of power shouldn't be a problem then.

So it is lack of air that causes the loss of power when switching to propane? Not enough oxygen for good combustion?

 

[kenmac]

propane will have a higher btu than the nat gas .So it will tend to have more power

 

[dbdartman]

So it is lack of air that causes the loss of power when switching to propane? Not enough oxygen for good combustion?

No, it's lack of BTU's. Few readily available fuels have the BTU capacity of gasoline, which is the main reason it's been the fuel of choice for nearly 100 years.

 

[chadincolo]

No, it's lack of BTU's. Few readily available fuels have the BTU capacity of gasoline, which is the main reason it's been the fuel of choice for nearly 100 years.

BUT...putting more LPG into the engine makes up for it...just putting a dual fuel kit on a stock (correctly sized for gasoline) carb will make the engine a little starved for fuel/air and have to work a little harder. You will never get the same mileage and power (naturally aspirated) on propane as with gas, but 30% is crazy...5-10% is realistic with a correct set up.

Just signed a contract for propane, $2.29 per gallon, 10 cents off if I pay within 10 days. Even at 90% the mileage of gas, I'm still equivalent to $2.43 gas...and for what I use it for, power isn't much of an issue...even if it was, if I put headers and a good exhaust on, will be right where it was stock with gas... It is an option, and for some applications, a VERY good option to use LPG...

 

[jinjimbob]

BUT...putting more LPG into the engine makes up for it.

Yes, and that is why oil gives you the most BTUs over propane/natural gas.
That is why oil is used.

 

[heehaw]

according to a local propane co: to put propane on my vehicle i would have to pay a $300 a year permit fee: maybe a little less, he wasn't 100% sure: but what does it take to fill your vehicle from a home tank? would i have to buy a propane pump??
heehaw

 

[chadincolo]

according to a local propane co: to put propane on my vehicle i would have to pay a $300 a year permit fee: maybe a little less, he wasn't 100% sure: but what does it take to fill your vehicle from a home tank? would i have to buy a propane pump??
heehaw

Taxes are determined at the state level on propane vehicles (from what I can tell) so will vary by location.

You need a tank with a wet line (most rental tanks won't, liability reasons) and a hose with proper fittings to fill. You can't fill completely full without a pump, but can get them close if the main tank is full. Or go to the nearest propane dealer, most rental placese, some gas stations and of course propane suppliers can fill.

Oh, and someone to help you the first time and teach you how to vent the tank and get it filled....better safe than sorry.

 

[Highbeam]

Seems to me... and I may be a little confused, but if you have a wetline pulling from the liquid portion of the mother LPG tank that the pressure in the "mother" vessle will always be the vapor pressure of the propane for a given temp which is approximately 120psi. I see no reason that you should need to pump liquid propane from the mother to the daughter tank. The pump will make it move faster but the equillibrium point will be 120 psi in both. Propane was always so much more expensive to burn that people blew it off.