f150 on lpg

LPG = Liquid Propane Gas, the type you see in pressurized gas cylinders. Some people, espically those that drive trucks because of the storage room, convert their vehicles to run on LPG or gasoline. It is also used a lot on low emission lifting equipment like forklifts used indoors.

Gas has about 25% more energy than a like amount of propane or in other words, it takes 1.25 l of propane to equal 1 l of gas. Milage for a propane vehilce is proportional to that. I ran a few fleet vehicles on propane and I thought the milage was about 80% of gas.

Propane is about 60% of the price of gas around here so there is still a net savings running of propane.

Comparing the cost of 1 litre of gas with the amount of propane to deliver the same amount of energy:

1l gas = $1.10 1l Propane = $0.68 1.25 * $0.68 = $0.85 Cost of amount of propane to equal 1l gas $0.85/$1.10 = 77% Relative cost of propane compared to gas

I use something close to 20l/100 kms in my F150 and I drive about 20000 kms per year so I use about 4000l/year. This year, if gas stays at $1.10 per litre it will cost me $4400 for gas.

$4400 * 77% = $3388, a difference of $1012 per year. I don't know how much a conversion is these days since I haven't had to pay for one in a long time but I'll make a guess at $3000. This means that I'd have a three year payout before I realized any savings.

Remember that the engine will also lose considerable power and that is a consideration if you tow or haul stuff around. It's a pickup right? I've thought about the conversion from time to time but it's not really worth it to me for my personal vehicle.

I'm sure this was more of an answer than you were asking for but I kind of wanted to work it out for my self so there you go.

Stephen N.

On Sat, 15 Apr 2006 12:07:56 -0700, David F. Mishiwiec Sr. rearranged some electrons to form:

propane

Don't know if I agree with all of that, Father used to manage a rather large propane yard in central Florida for a few years and his company vehicle was a 4.3 V-6 Chevy 1500 p/u. He said the power seemed the same, vehicle ran on ether propane or gasoline. He did say fuel mileage was slightly (his words) less than gasoline, he drove 62 miles one way, 85% freeway.. Of note, if the vehicle has cast pistons instead of forged expect to burn holes in them. One thing I discovered is the engine oil stayed a lot cleaner, and I did some moon lighting for his shop and the engine internals looked better on tear downs. Temperature and elevation may play a role. For a long time at Sunshine Speedway there was a guy running a '64 Belvedere on propane, did damn good with it. Biggest limitation he had was the engine he was running, there just weren't any after market parts for it, and of course the car was heavy as hell too.

Whitelightning

I wouldn't swear by my calculations but I think they are pretty close. I ran three taxis on propane for a number of years. There is definitely a noticable power loss and I used to say that the milage was 20% less than for gas but I did not run a gas vehicle to compare it to. Other similar vehicles seemed to be getting about that 20% extra milage running on gas.

At the time we were running full size Oldsmobiles, Caddies and the like so we were pretty quick to convert them to propane. It was only a few months to payout on the conversion.

You are right about the oil and the engine staying cleaner. It never seemed to go black, in fact it was hard to see it on the dipstick! We did still change it every week or so because we thought that the oil additives might break down over time and use. Don't much about oil so I don't know how true that is.

Stephen N.

I don't know how available LPG is in the states, but here in OZ it is very common. Someone mentioned taxi's and I would say close to 100% of them here run on LPG. current fuel price (west coast australia)AU$1.30 / litre. - us$3.55 /gal current LPG price AU$0.61 /litre - us$1.68 /gal

and thats in the capital city. Here in the north west we are paying au$1.50 / litre or more.

Darren

snipped-for-privacy@> Can anybody tell me what the best economy I can expect from an lpg

My '89 F150, 5lt, on petrol, used about 20 lt/10km. I converted to lpg (dual fuel) many years ago and, from memory (I have not checked for a long time) , I use about 50% more lpg than petrol. There is some loss of power but not enough to notice. These figures are dredged from memory so I won't swear by them.

One thing I would warn anyone who switches to dual fuel - keep your petrol tanks full and replace the contents at least every 6 months because petrol deteriorates. Just have a schedule where you switch to petrol and empty one of the tanks regularly. And then refill.

I made the mistake of only using one tank and not always keeping it full. The other tank remained empty. Both tanks (and both senders) suffered serious corrosion. I replaced one tank and sender and the other was written of - I now only use one tank (no problem as I use mainly lpg anyway but I pass on the lesson to others so they can avoid my mistake).

In other respects use of lpg gas been uneventful. Another thing - with a F150 you need two lpg tanks - 100lt capacity in all - to have a reasonable range. Mine are fitted on on each side behind the driver/passenger (my vehicle is fitted with a flat tray rather then a box.

Thanks for the Nice Informative Post!

If you have a carbuerated engine (versus a fuel injected one), even though propane has 20% less energy per gallon, it isn't rare that you will get better mileage with propane due to the inefficiencies of carbs. This is especially true in you have the 460 engine (which you don't).

If you rebuild the engine to run on propane only (higher compression ratio), your propane mileage will be pretty close to the gasoline mileage.

thankyou for the feedback,It looks like whichever way i turn this kind of vehicle is going to hit the pocket hard with fuel costs