I have a 2003 futura wagon with dedicated lpg. I recently nearly ran out of lpg on a country trip and found myself only being able to travel at 40km/h for the last two kilometres before I drove into a service station. I filled up o.k with no problems. However I asked my mechanic what happens when you run out completely. He suggested using a normal 9kg bottle of gas with an attachment for the car, as I tow a caravan with bottled gas. However when I looked at this option I found out that the lpg used for the small cylinders is pure propane where the car lpg is a mixture of propane and butane. If I used this option to get myself out of trouble would the pure propane harm my engine or catalytic converter? What are the ramifications if any of actually running out of lpg?

What you need to remember, your lpg 'jerry can' will only donated until pressures in both tanks equalize. Also, you'll need to raising the lpg bottle above the lpg tank while holding the bottle upside down so have your connection long enough so you can rest the bottle on your shoulders.

That's the disadvantage of having an LPG only car, you run out of LPG and you stop, simple as that, tow truck time

I think you'd find that the option he suggested is both highly illegal and dangerous, and I'd hope he was just having a joke with you.

There are stations that sell pure propane for auto use.

I've got an EF converted to LPG. Converter said that nothing would be damaged if the car ran out of lpg.

I'd say it's less dangerous than operating a BBQ...

I believe that RACV ..... do exactly that.

I know for a fact that up near Mt Buller, the RACV tow the car to the servo if you run out of LPG...

Also, it depends, if they're talking about using an adapter of some kind that fits to the LPG filler, then that's ok, but you can't have something plumbed up in the lines some other way.

simple answer. don't run out of gas

When I drove a dedicated gas taxi and it ran out (because of the extremely accurate fuel gauge......not) the RAA would tow you to the nearest servo.

I have seen an adapter hose from a 9 kg bottle to standard filler connection but that being said the gas fitter that made it admitted it was not legal.
He was using it in his shop to put an in initial bit of gas in new tanks.

Ive used one of those hoses.

The interesting thing is that Autogas often is the same blend as LPG. Its a propane/butane mix, with more butane the further north you go in Aus (I think thats the way).

Which is why LPG is sometimes so hard to tune... the quality changes.

Now an interesting point - At least you were able to go 40. In a petrol car you would have stopped. In an LPG car you get a warning that your running out, and then reduced functionality

Nigel

As far as i'm aware 100% propane is the best fuel, whereas normal pump LPG is around 90% propane 10% butane. I found that fuel quality varied from station to station.

From what i've heard a permanent bottle connection point plumbed into the vehicle's LPG system is not uncommon. I wouldn't have a problem using one. The connection point itself shouldn't hold any greater risk of leakage than any of the other fittings in the system. Neither can i see the filling method holding any more risk than using an LPG bottle in other ways, indeed, less risk than when an ignition source is nearby, which is often the case with other uses.

Holding the bottle upside down? I imagine that means rather than pushing gas through, the pressure pushes the liquid through, much quicker and gives complete transfer? Holding it above the top of the car's tank also ensures complete transfer, and the higher you hold it maybe the faster the transfer?

Using a 9Kg bottle gives about 20l, but only a portion of that will transfer the first time. The pressure in your tank, and the Gas bottle will equalise.. and then you drive. When you run out again you do it again.

As for LPG - some of the stuff up in FNQ gets lower than 80/20 I hear.

Nigel

How about that . . . nifty.

I'll probably never forget an extreme economy run i did in my 350chev powered straight gas one tonner. I left a town in the late afternoon in the hills way above Coff Harbour, maybe it was Ebor or near there, and about 120kms later realised that i should have filled up because i had a long way to go and all the service stations would be closed. Rather than stopping and thinking it through like i should, i decided to keep going, and as i got further and refined my calculations i realised that by normal consumption i would be at least 150kms short. Normal consumption was around 18-22L/100kms driving fairly hard, considerably less driven economically, as i fully found out. So i started coasting down hills in neutral and crossed my fingers. It was cold and raining and i was reaching breakneck speeds rolling down some of the hills trying to conserve as much momentum as possible. The road just seemed to keep going and going, up and down long steep hills that sucked all the more gas. There weren't many towns, so each had a certain prominent quality, as i eerily passing through them in the dark. More and more hills and hours passed and it just kept going. And going. Then it was mostly downhill for a while as i descended the range, but it was only small relief as it could still run out and i would be stuffed. Then i was on the flat, and it kept going. Somehow, eons later, it had kept going, and here i was entering the final town where i could get fuel, but only just, as they were about to close. I happenned to meet my father and was almost tempted to do other things . . . as it just seemed to be driving on nothing . . , but reason saw me go and get a fill.