nico

Both LPG and CNG are liquid when compressed. They are a gas (and unusable in vehicles) under normal pressure and temperature. When you see cabs, city cars, and Civic GX's running on natural gas, it's compressed at a high PSI into a fuel cylinder.

Propane has 74% of the energy of gasoline, and CNG has 25% of the energy of gasoline.

My 70's Ford pickup ran on propane. It was cheap and convenient at the time. I don't think current propane conversions are CARB legal, so I haven't done much research into current conversions.

toyota-erik

My point was that if they step down the pressure before it gets to your house, how would you fill a bottle? If you cant compress it till it changes from a gas to a liquid, you wouldnt have the same volume of fuel as a LPG tank and you wouldnt go very far.
FYI, I got my yota to start at -40F(ambient). The trick is to bring your tank in the house at night.
Disclaimer; I do not recomend storing LPG tanks indoors.

nico

If you're talking about Natural Gas, that would be Phill, from FuelMaker. It runs around $3K. It takes about 8 hours to fill a 10 gallon tank, but the upside is that it runs you the equivalent of $1/gallon. And NG is native to the US, and highly abundant, so it's not being imported from elsewhere.

odtoy

gotpropain.com has a set up now where you can run your 22r on propain when wheeling and still switch to gas when on the road. They also claim you dont loose any mpg and it runs just as good. I realy would like to do the kit but A efi switch would be the best all around i think.

toyota-erik

I struggled with this decision too. For a trail only rig I would still recomend the Propane system even after all that I've said. It is one thing I dont have to think about on the trail.
Just dont do it to save a bunch of money on fuel.

Al's Chop Shop

i've also been doing research on running LPG to save some coin. they are selling LPG for about $2.50/gal locally. i have friends that have pieced together systems and say i can find good used units for about $350. i shot high and calculated for $750 total cost (gotpropane.com is overpriced!). i figured a 20% decrease in fuel mileage, and compared to $4.10/gal for gasoline it would take about 30,000 miles to pay off the difference for the kit at $750. if i could do it for $350 i'd be breaking even in just over an oil change. oh wait, i won't be changing my oil as frequent because LPG does not contaminate the oil with carbon like gasoline.

i plan on running a dual fuel setup so i can run gasoline if i can't find a fill station (reports locally is after 7pm you're screwed) and i'd have a 10gal tank mounted in a diamond plate tool box in the bed.


you will lose about 15-20% fuel economy by running propane. you will need to advance the crap out of your timing to get some of that back, but then when you run gasoline you'd better bring the timing back down or you'll have severe detonation.

Al

sethmcalister

Al, how did you get the 20% decrease in mpg? I know I can't believe what the website says, but gotpropane.com says no loss in mpg. However, they make clear that their system is "high performance." Do you think that has anything to do with it and that your system wouldn't be "high performance? Just curious is all, have been thinking of myself for further down the road.

Al's Chop Shop

i read a decrease up to 20% from other websites. i don't have anything bookmarked but start on google. also the people i've talked to that run it notice a slight decrease in power. like i said, you can get some of that back by advancing your timing, but you can't switch back to gas without having to retard it back to normal.

honestly, if gotpropane.com only runs them on trail only hardcore rigs, how in the world can they even say they get the same mileage as gas engines? i'm not trying to bash them or anything, a bud of mine has their kit and loves it. its a great way to buy everything but the tank, but i know i can piece a system together so much cheaper. if they don't have experiance with them on a street legal driver rig they have no business stating the same fuel mileage.

and unless it makes you go faster, its not 'high performance' any more than those window stickers the ricer guys put on their windows.


edit to my above formula... i just found my sheet of paper with my math.... the system costing $750 would pay for itself in 11,718.75 miles (about a year). dunno why 30k popped in my head. this is with LPG at 2.80/gal and gas at 4.25/gal, estimated fuel economy with 17mpg gas and 15mpg propane. price per mile on pane is $0.186 and gas is $0.25. so about 11,700 miles to get that $750 back.

Al

toyota-erik

Al is right. A decrease in power and mileage is a fact. The guy that convinced me to switch to propane, sounded like an ad for GotPropane saying I wouldnt lose power. I wasnt falling for it.
Maybe If you built an engine especially for propane the difference wouldnt be as noticable but you can only get so much energy out of a gallon of propane.
Im still happy with the system overall.

Zombie

So if I am under powered now running 33's on the street it would be worse if I converted to propane, Right? But it would be cheaper than running gas.

red1983

iTrader: (1)

I called got propane... the owner answered. I asked him if it is reasonable to use on a daily driver, he said he first devolped these kits for the reason, and then figued out how great it was for wheeling. So think they have a lot of experience with propane vs gas milage but they wouldn't/ couldn't give me numbers... they said you may loose gas milage, you may gain. They wouldn't know. I did find a lot of sites that said the cost of the conversion should be much cheaper than got propane, but I think one is paying for their system they devolped, and hopefully, if it is in line with what they claim, is a little higher performing. With my gas milage not being great I would think it would only improve??

brooklee1000

The "sytem" they developed is just Impco brand equipment that they mark up severely to sell to those who are unwilling to hunt around for stuff. I have a mixer, convrter, vacuum shut-off switch, and 100lb auto grade tank that I got all for $500. Look around at the local wreckers, you can find most of what you need for cheap. I got my stuff from a conversion shop, some of it brand new, and it was still cheap.

bigt

there kit would proform the same as forklift kit.,,

i am currently paying off my 1987 pickup.. and i plan to propane it at the end of summer or over winter...

i already have 2 re's . and carbs and gas tanks and all stuff i dont wanna deal with after i get it plated... shes getting the

nico

With propane having 25% less energy than an equivalent amount of gasoline, I don't see how your mileage could possibly go up, unless you tore into it and raised the compression to take advantage of the higher octane.

I talked to a friend of mine at CARB, and she said the complexity of a CNG coversion didn't make any financial sense on anything but a vehicle that was engineered for it. To make any power at all, you have to run 12.5:1 compression, plus the cost of the tanks are pretty steep. I don't think it'd make any sense for the RN48, but the FJC might be another story.

(note that above I said CNG - Compressed Natural Gas - and not LPG - Liquid Propane Gas)

JasonWin

I think I'm just gonna wait for hydrogen to become economical...

Al's Chop Shop

tanks are cheap. maybe the most expensive 'part' of the swap, but they aren't expensive when you get them used. they frequently pop up around $150 for a 10 gal tank locally.

you are correct that higher compression will make much more power, but 22rs have decent enough compression in stock form to run 'pane well. 20r's are much lower on compression and do not do very well on 'pane. i have a friend that swapped his 20r to 'pane and hated it. he couldn't turn his 36's in the mud.

if lpg doesn't make economical sense, how can i calculate saving money by running the system? my math isn't flawed.... depending on your local cost of LPG can vary, but as long as your cost of lpg stays well under the cost of gasoline you can't really go wrong.

Al

4Skanker

My current project is a 22RE running propane. All of my components have been gathered up from wrecking yards. Even after fabin up a turbo header and bolting up an IHI turbo , I'm under $400...expensive part has been my ignition system , more cash than I care to think about right now LOL.

Heres a list:
-1 Impco 200A mixer 3" inlet/outlet for EFI setup ( no throttle plate , came off a dual fuel V6 Ford )
-1 Impco L-converter
-1 Impco Vac shut off
-1 Fork lift tank = 33 lbs aluminum tank
-1 IHI T-Bird Turbo Coupe turbo/intercooler
-Home fab'd Turbo header useing 1/2" plate for the flanges and NSP weld els
for the tubes
-Couple aluminum tube cold air kits off various import cars = Turbo plumbing
-MSD 6 offroad ignition with offroad rev limiter , MSD Boost Timing Master , MSD blaster coil

Its all on a rebuilt 22RE in a blow through setup , the turbo's oil return is plumbed into the pan and the oil feed is taken off the oil pressure sending unit. The stock T-Bird waste gate is set for 8 lbs boost so thats where my starting point is going to be...an adjustable waste gate is in the works and a BOV will be used eventually.
The converter is referanced on the boost side of the intake instead of to atmospheric pressure...if you dont do this the increse in boost pressure will give you a lean condition , at higher boost levels it will cease to deliver fuel alltogether.
When she's all buttoned up I'll update with how it works...and what I'd change if I was to build another.

trbizwiz

Propane may have fewer btu's, but what you arent taking into consideration is the unburnt gassoline. THis is why the ignition systems like Jacobs provide a little performance. With propane you wont need a fancy ignition system, the propane will burn completely. This info is based on lots of reading threads, not on first hand experience, so take it for what it's worth.
That being said, anybody do this on a 3.0? I have been planning on buying a 22re, but I found a deal I cant pass up on a 92 with a 3.0, I still want to do the conversion. You guys that sourced your own parts, do you mind posting part numbers?

Al's Chop Shop

you are right, propane burns clean and doesn't leave carbon deposits on cylinder walls like gasline. so that means your oil won't be contaminated by carbon and will last longer before breaking down.

Al

toyota-erik

Well, I just got back from my month long, cross crountry, 4-wheelin trip and Im happy to report that the propane worked great at over 13,000 feet. There was no noticable difference other than the loss of power that every vehicle has. This was also the first time running propane outside an offroad park or not running thru 3 feet of snow. I started in Ourray one morning and drove to the Black Bear trail head, took Black Bear to Telluride and came back to Ourray on Immogene and used only 7 gallons of propane. Those of you that are familiar with this trail system know that this pretty much takes a whole day.
Also, I found out why Ive been having trouble getting my bottles filled at some places. A while back, there was a federal law stating that certain types of tanks had to have an automatic shut-off valve to prevent them from being over filled. Forklift tanks are specifically excluded (along with several other types of tanks) in this law. I argued with some girl for 5 min about this and it was posted on a sign right in front of her.
I also got 2 new adapters and can fill them anywhere. Note: the forklift tank fitting looks identical to the grill tank fitting but are NOT interchangable even though the grill tank fitting will thread on to the forklift tank.