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Anyone got dual LPG tanks?

20K views 17 replies 13 participants last post by  Darryl caton  
#1 ·
After getting only 280km to a tank of LPG yesterday (highway running, headwind, full throttle holding 110-115 up hills, air con on, and only filled it with 75 litres and I couldn't fit any more in, presume this is a summer/heat thing) I've been thinking if it's possible to fit a second LPG tank?? A bit more range would be handy!!!

Does anyone have such a setup?

If so, what's involved? I presume you'd fit it inside the cabin behind the second row of seats? Where is the filler point? How do you switch between tanks? The always important question - what did it cost? Anything else??

I haven't contacted a gas place, thought I'd ask the forum of knowledge first!!!!! :p
 
#3 ·
im keen to the same thing soon too, there are a few ways of doing it depending on what you want/need, second tank is connected via a valve the lets the gas only go into one tank and not back the other way so you just use one filler, if u really wanted it you could have them seperate with 2 fillers and a switch between the 2 but not needed and more work(cost) ive spoken to people who had it done with a re-tested second hand tank supplied and fitted for $700ish and i asked at my gas place and dont think he was keen cos he quoted $1500 for new tank fitted but he bitched about the job making it sound all hard and expensive so shop around and under $1000 should be easy.

cheers shannon
 
#4 ·
Had 7 LPG vehicles but never a twin-tank setup, though I've seen them. I believe the most common setups are either a dash-switch to manually switch between cylinders or an automatic solenoid arrangement. You can have a cylinder on the floor in the back of your Patrol, it's done all the time in older wagons. In Vans you have to protect the cylinder with some sort of structure - usually a wooden box with access to the emergency shutoff valve but in passenger vehicles it's not usually compulsory. Find a good gas place & discuss options.
 
#5 · (Edited)
A twin LPG tank setup is really quite a simple set-up. I've fitted about 4 of them, even a triple on a motor-home, and there is nothing complicated about it at all. They share the same fill hose and you use a hydrostatic valve to connect the 2 service lines. This makes the 2 tanks drain simultaneously. When I left the industry, there was no interface that allowed a one gauge to read the combined level; you had to have 2 gauges. This may have since changed.

There is no reason other than w@nk value to have a switch to change between tanks. It might be cool for the first couple of weeks, but after that, it will be a totally unnecessary annoyance.

The cost is the most prohibitive part. If you've got the space, there's a tank to fit almost ANY application. Just don't expect to be shy with the $$$ and be prepared to lose a bit of real estate in the cabin when it goes in.

As far as fitting the tank inside, the tank must have a "compartment" on it. In other words, it must have an air-tight enclosure that houses the valves and fittings. This compartment is then vented to the outside of the vehicle through a big flex hose that houses the fill hose, service line and the electrics. There is no requirement for a protective enclosure around the tank. (in QLD, at least).

If the tank is fitted outside the vehicle, this is not necessary as there is no danger of asphyxiation or build-up of fumes. External tanks must also have a stone shield fitted if they are underneath the vehicle.

Hope this helps,

Rob.
 
#18 ·
A twin LPG tank setup is really quite a simple set-up. I've fitted about 4 of them, even a triple on a motor-home, and there is nothing complicated about it at all. They share the same fill hose and you use a hydrostatic valve to connect the 2 service lines. This makes the 2 tanks drain simultaneously. When I left the industry, there was no interface that allowed a one gauge to read the combined level; you had to have 2 gauges. This may have since changed.

There is no reason other than w@nk value to have a switch to change between tanks. It might be cool for the first couple of weeks, but after that, it will be a totally unnecessary annoyance.

The cost is the most prohibitive part. If you've got the space, there's a tank to fit almost ANY application. Just don't expect to be shy with the $$$ and be prepared to lose a bit of real estate in the cabin when it goes in.

As far as fitting the tank inside, the tank must have a "compartment" on it. In other words, it must have an air-tight enclosure that houses the valves and fittings. This compartment is then vented to the outside of the vehicle through a big flex hose that houses the fill hose, service line and the electrics. There is no requirement for a protective enclosure around the tank. (in QLD, at least).

If the tank is fitted outside the vehicle, this is not necessary as there is no danger of asphyxiation or build-up of fumes. External tanks must also have a stone shield fitted if they are underneath the vehicle.

Hope this helps,

Rob.
Can I put a t piece in main line and turn on or off one tank
 
#6 ·
Ive got 2 tanks in my shorty. One under the rear and one smaller one behind the front seats. 175 litres useable all up. I had the 2nd hand 80 litre tank fitted about a month ago along with a gas research throttle body and converter which I supplied for $1600. That included dyno tuning as well.

The big under car tank uses a seperate guage and the other uses the factory gauge.

Its got me confused how they are a setup because they dont empty at the same time.

The lines run from the filler to a T piece to each tank. Then out of each tank to a T piece and from there to the engine.

When it was first fitted the smaller tank would completely empty then the bigger tank would start emptying. When I went to tassie a few weeks ago the car surged and now the bigger tank empties first then the smaller one empties.

I dont understand why they empty one at a time. My thinking is that they would equalise and empty at the same time but meh, it works and I get decent range.
 
#7 ·
HiFiRobbie said:
A twin LPG tank setup is really quite a simple set-up. I've fitted about 4 of them, even a triple on a motor-home, and there is nothing complicated about it at all. They share the same fill hose and you use a hydrostatic valve to connect the 2 service lines. This makes the 2 tanks drain simultaneously. When I left the industry, there was no interface that allowed a one gauge to read the combined level; you had to have 2 gauges. This may have since changed.

There is no reason other than w@nk value to have a switch to change between tanks. It might be cool for the first couple of weeks, but after that, it will be a totally unnecessary annoyance.

The cost is the most prohibitive part. If you've got the space, there's a tank to fit almost ANY application. Just don't expect to be shy with the $$$ and be prepared to lose a bit of real estate in the cabin when it goes in.

As far as fitting the tank inside, the tank must have a "compartment" on it. In other words, it must have an air-tight enclosure that houses the valves and fittings. This compartment is then vented to the outside of the vehicle through a big flex hose that houses the fill hose, service line and the electrics. There is no requirement for a protective enclosure around the tank. (in QLD, at least).

If the tank is fitted outside the vehicle, this is not necessary as there is no danger of asphyxiation or build-up of fumes. External tanks must also have a stone shield fitted if they are underneath the vehicle.

Hope this helps,

Rob.
Just to add to this, apa and possibly manchester make 0-45 ohm sending units. as long as the tanks are the same size, these can be used with a normal lpg led gauge, this will, when wired up in series, show total lpg level, it won't work though if you have the dash gauge hooked up to show lpg level, then you will need a plain led gauge for the new tank
 
#8 ·
I did my whole gas conversion on the cheap. The gq cost me $1500 and the gas was previously fitted to my Nissan Urvan (fitted most of it my self and paid $300 for a saftey swithc, some wiring and gas mod plate, got the $2000 rebate = free patrol). I fitted the 80lt tank inside the rear of the wagon but was only getting 320km to a tank so a mate got me a 100 lt tank from the wreckers he works at. Fitted it myself with its own filler in the rear step opposite the filler for the 80 lt tank. I have very little luggage capacity but I can do a return trip to my girlfriends place (450km ) and run to work all week, filling up only when gas is cheap, usualy Tuesdays at around 44c pl. My small tank always emptys first and it is the only one with a guage. I bought a switch to turn each tank on and off indipendantly but after using the set up as it is, I can see no real need to swich between tanks.
 
#9 ·
dansedgli said:
I dont understand why they empty one at a time. My thinking is that they would equalise and empty at the same time but meh, it works and I get decent range.
Don't forget that before the LPG gets to the convertor, it is still in liquid state. So what is happening is the higher tank is draining into the lower one, just like water or petrol would.
 
#10 ·
HiFiRobbie said:
Don't forget that before the LPG gets to the convertor, it is still in liquid state. So what is happening is the higher tank is draining into the lower one, just like water or petrol would.
The tank that empties first now is the lower tank which is mounted where the standard fuel tank usually goes.

The higher tank stays full until the lower tank is empty.
 
#11 ·
dansedgli said:
The tank that empties first now is the lower tank which is mounted where the standard fuel tank usually goes.

The higher tank stays full until the lower tank is empty.
Hmmm... ...ah... ..er... ...I got nothin'!
 
#13 ·
Andrew44 said:
I talked to a guy in a service station once who had connected up two LPG pumps to his car. When I asked him he said he had deliberately had the second tank installed with its own filler so that he could save time by filling both tanks at the same time.
I've also got a filler for each tank on my hilux (one either side of the number plate on the back of the tray),makes fiiling heaps quicker an at the same time if i have a problem with 1 of the tanks i can isolate it an still be able to use the other
Also running hydrostatic valve between the 2 tank outlets but it makes no difference to which tank drains first sometimes they drain equally other times 1 will drain before the other
 
#14 ·
Hey thanks guys, some very interesting comments.... didn't even occur to me that the two tanks could be filled in parallel from the one fill point....

Lots of decisions to make, next step will be to speak with some Canberra gas fitting mobs to see what the bottom line will be!
 
#17 ·
My neighbour runs on 84 Landcruiser & put dual gas tanks on it, they are both underneath & he loves it. the big One is at the back & a smaller one runs along the left under the car from memory. He has a tribe of kids so inside was not an option. He still has a 40 litre petrol tank (underneath on the right) as reserve for outback trips when LPG is scarce & says that he would not be without the petrol tank going bush which really makes sense to me. (I guess he is not doing any serious off roading though or he would have a Patrol;) )