LPG quality?

[LuxyBoy]

Hi All,

Please excuse the ignorance but is there any difference in quality between the different service stations LPG?
I only run BP diesel, but recently got LPG fumigation put on (fuel:Km post will be coming when i have enough data) and just thought i would ask the question before pumping it in blindly.

[RaginRover]

I find a bit of a variation in quality from time to time - I haven't had any with BP LPG.

It might be one tank in 30 that I found a difference in when I was filling up all over the shop. For about a year I worked practically next door to a BP so I just started filling up there with a 2c/L discount card and didn't ever notice any variation.

Tom

[paultherocksta96]

On my Mav I've found that shell gas has been most expensive and least powerful/fewer k's.

[Beastmavster]

There's a minimum octane standard but unlike normal fuel it's not all the same octane - the propane blend levels vary.

[F'n_Rover]

i also thought the propane / butane blend varied depending on wether the tank was full or getting empty? Aparantly the gas blend seperates into layers when stored. There are a few outlets that sell 100% propane for only a few cents more a litre. Find these places - its the good stuff.

[Beastmavster]

Depends on stuff like if they use the same truck to fill up the LPG tanks as the one fro Barbecue gas refills.

While the more properly refined fuel is worth a little buit more, with the transportation costs it can be cheaper to top up both the LPG tank and the BBQ refill tanks with the one truck.

Very common practice and you get the good fuel cheap.

In higher LPG selling outlets in metro areas it's less likely to happen.

[-Mick-]

i also thought the propane / butane blend varied depending on wether the tank was full or getting empty? Aparantly the gas blend seperates into layers when stored. There are a few outlets that sell 100% propane for only a few cents more a litre. Find these places - its the good stuff.

is it worth while searching out the good stuff though for the average lowish compression dual fuel converted vehicle??? Average petrol vehicle compressions around 9:1 wouldn't be anywhere near taking advantage of the octane rating of regular lpg.... let alone a more refined better quality lpg

Its a bit like those people who run their low compression cars on optimax....... they don't need it..... they don't make use of it..... the car doesn't run any better as a result..... but its "soooooooooooo much better"

That said though for Luxyboys diesel fumigation setup it could be very worthwhile. He's dealing with big compression and could really benefit from it

[Moose45]

I would have to say yes there is a differance in lpg at differant
servo`s. Like mentioned earlier depends on mixture of propane/butane.

Sometimes I find it alters the idle mixture, rough idle/hard starting, although not as noticable in higher revs.
Then next fill up might be all ok.

[Beastmavster]

Remember the minimum equivalent octane that LPG can be sold at is legislated at 114.

(not that it actually has 114% octane or even 1%, but that's the RON equivalent)

If you score 120 octane or better good luck to you - but you tune for 114....

[Guy]

Depending on seasons the mix's vary to help stop converters icing up in colder months.. around greater metro vic allot of gas is BP gas (so I am told)

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

[ISUZUROVER]

Depending on seasons the mix's vary to help stop converters icing up in colder months.. around greater metro vic allot of gas is BP gas (so I am told)

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

This is correct. More butane and less propane in winter. There could possibly be some slight variation in the mix between the top and bottom of the tankful but I doubt it would be noticeable.

[Beastmavster]

This is correct. More butane and less propane in winter. There could possibly be some slight variation in the mix between the top and bottom of the tankful but I doubt it would be noticeable.

Might be noticable when you first start the car, but once you're mobile all the fuel would be constantly mixing.....


slosh slosh

[bazooked]

i though i was seeing things between the 2 different brand servos i use, i try to use bp as much as i can but have used caltex occasionally, i get about 20kms less per tank on the caltex gas.

[F'n_Rover]

Depending on seasons the mix's vary to help stop converters icing up in colder months.. around greater metro vic allot of gas is BP gas (so I am told)

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

I can't see how it would slosh around? The tanks weigh around 5 tonns and are filled with maby 20,000 litres of lpg. And they are also bolted down into the earth.

With regards to the octane rating - there is more to a good fuel than just octane ratings. Its energy rating is also a variable.

[Hamo]

On my Mav I've found that shell gas has been most expensive and least powerful/fewer k's.

I.ve found the same in my 45 troopy also when i fill at the local shell my 70 ltr tank takes 75 ltrs from dead empty but when i travel the 60 klms to the next town and fill at the safeway servo the tank only takes 67 lts?

[-Mick-]

Depending on seasons the mix's vary to help stop converters icing up in colder months.. around greater metro vic allot of gas is BP gas (so I am told)

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

I can't see how it would slosh around? The tanks weigh around 5 tonns and are filled with maby 20,000 litres of lpg. And they are also bolted down into the earth.

With regards to the octane rating - there is more to a good fuel than just octane ratings. Its energy rating is also a variable.

I think your in car tank sloshes around I wouldn't like to see the servos main tank sloshing around either............ especially the underground ones

[Guy]

i also thought the propane / butane blend varied depending on wether the tank was full or getting empty? Aparantly the gas blend seperates into layers when stored. There are a few outlets that sell 100% propane for only a few cents more a litre. Find these places - its the good stuff.

While it is possible for Propane & Butane to separate, with Specific Gravities of 0.51 & 0.58 and very low viscosities and turbulence created by pumping, and thermal effects it is most unlikely.

[Andy_B]

I've recently got the Disco LPG tuned, and I was talking to the guys their, they said that shell and BP, have some the worst quality LPG. He also mentioned that mixing ration of propane to butane was a gentlesmans aggreament.

He found a place that sells 100% propane, and when he uses propane his fuel consumption goes from 5km/L to 9km/L in his GQ.

[RaginRover]

I've recently got the Disco LPG tuned, and I was talking to the guys their, they said that shell and BP, have some the worst quality LPG. He also mentioned that mixing ration of propane to butane was a gentlesmans aggreament.

He found a place that sells 100% propane, and when he uses propane his fuel consumption goes from 5km/L to 9km/L in his GQ.

Care to share the name of the place he fills up ?

How much did he charge for an LPG tune and what is the company name - I would like to get mine tuned shortly after I finish tinkering - see if they can get it working better than I can.

Thanks
Tom

[Emo]

All the big companies vary the mix of butane and propane depending on the time of year and what stock is available.

[LuxyBoy]

I've recently got the Disco LPG tuned, and I was talking to the guys their, they said that shell and BP, have some the worst quality LPG. He also mentioned that mixing ration of propane to butane was a gentlesmans aggreament.

He found a place that sells 100% propane, and when he uses propane his fuel consumption goes from 5km/L to 9km/L in his GQ.

Where?
Is there any disadvantage to not having any butane in it?

[ISUZUROVER]

I've recently got the Disco LPG tuned, and I was talking to the guys their, they said that shell and BP, have some the worst quality LPG. He also mentioned that mixing ration of propane to butane was a gentlesmans aggreament.

He found a place that sells 100% propane, and when he uses propane his fuel consumption goes from 5km/L to 9km/L in his GQ.

Where?
Is there any disadvantage to not having any butane in it?

I think there would be significant disadvantages in cold weather - especially when starting. But probably no significant disadvantages in summer.

[awill4x4]

Some interesting facts on LPG history, international pricing and trends can be read at http://www.lpgaustralia.com.au/displayc ... iclenbr=10
Also some interesting pricing comparisons over a 5 year period on both Propane and Butane with the "contract Saudi LPG" pricing.
http://www.lpgaustralia.com.au/displayc ... iclenbr=11 The Saudi contract price dictates our local LPG pricing. Interesting to note that Butane is actually more expensive than Propane and has been for over 18 months now.
Also that compared to the same time last year the Saudi price for Propane and Butane was $477 propane, $486 butane a year ago and is now $830 propane, $837 butane. I guess that explains our current high pricing here in Melbourne compared to what we're used to.
Regards Andrew.

[Hamo]

last week i filled at a bp and so far i have traveled 100ks (still 1/4 tank left) further than when i fill at a shell
Shell= 250ks max
BP= 350ks and still going?

& no i havent changed a thing

[bad_religion_au]

I guess that explains our current high pricing here in Melbourne

you serious, i love going back to melbourne because gas is cheap... been living on prices in the high 60cents per litre range for the last 6 months... 10 minutes out of adelaide cbd :(

[-Scott-]

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

Nope!

It's Liquefied. Liquefied Gas. What's a Liquid Gas? Is that like a Solid Liquid?

This was a (very early) question on "Who Wants to be a Millionaire?"

Dude went for "Liquid"

He lost.

DOH!

Scott

[bad_religion_au]

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

Nope!

It's Liquefied. Liquefied Gas. What's a Liquid Gas? Is that like a Solid Liquid?

This was a (very early) question on "Who Wants to be a Millionaire?"

Dude went for "Liquid"

He lost.

DOH!

Scott

if it's already a gas, why do we need the converter in line, why doesn't it go straight to the carby/mixer?

[ISUZUROVER]

if it's already a gas, why do we need the converter in line, why doesn't it go straight to the carby/mixer?

The bulk of the LPG in an LPG tank is in liquid form (liquified gas), the remainder is gas (it is stored in the tank above the vapour pressure) - over 120psi. You can either draw the gas off from the top or the liquid off from the bottom.

BBQ bottles, house bottles, and camping bottles, etc, etc, are vapour withdrawl systems, they are made to draw the vapour off the top.

Car LPG systems withdraw liquid from near the bottom of a tank, then convert it to gas before it is fed into the engine. I have heard people say that when you run the LPG level below the level that the pickup can reach, there is still enough gas in the tank to go for a few km's, but only at a slow speed since you are not drawing fuel off at a very high rate.

Here is a useful table of the properties of propane and butane:
http://www.lpga.co.uk/TypicalPropofCommercialLPG.htm

Liquefied Petroleum Gas (LPG) is the generic name for mixtures of hydrocarbons (mainly propane and butane). When these mixtures are lightly compressed (approx. 800 kPa or 120 psi), they change from a gaseous state to a liquid. LPG is colourless, odourless and heavier than air. A sulphur based chemical (ethyl mercaptan) is added to give it a smell like rotten cabbage, so that even a very small leak can be easily detected.

http://www.lpgaustralia.com.au/displaycommon.cfm?an=4

[LuxyBoy]

Yeah thats right Rover.
When i got mine installed he said when the gauge reaches the last light to turn it off and fill it up because the last 5L of the tank does not have the required pressure and the truck will run i little funny. Guessing he meant sloppy.

[Guy]

As for the layers separating in the tank I find that hard to believe as in the tank the L bit of LPG is LIQUID so the fuel would slosh around quite readily (the tanks are not baffled in any way )

Nope!

It's Liquefied. Liquefied Gas. What's a Liquid Gas? Is that like a Solid Liquid?

This was a (very early) question on "Who Wants to be a Millionaire?"

Dude went for "Liquid"

He lost.

DOH!

Scott

Someone best tell woodside petroleum that they are selling the wrong stuff
http://www.woodside.com.au/Home.htm (bout 2/3rds of the way down the paragraph)