LPG for GenIV

[JapSwede]

OK. I know - buying the 3.8LV6 wasn't the smartest of things considering fuel consumption, but, what to do when the environmentalists are reality unaware.

Short story - there are places you cannot drive a Diesel car to since a few years back here in Europe and I can't have a utility car which I can't utilize - at least I can't afford having an extra car just for those occasions when I need cargo space and not being able to use it when the "daily" is not around. (Wife. )

So, I've been considering LPG (the Brittish calls it that - not sure if you have it or what you call it though). However, I really do not want a big bottle in the trunk.

Seeing one lf the Aux. Long range fuel tanks being flush mounted behind the rear axle, got me thinking - wouldn't it be better to have a set of, say 3-4 small, round bottles mounted there instead, to save trunk space and avoid having gas leak risk inside the cabin? It would be really neat to have the LPG filling behind the very same lid as the normal fuel tank. Also, I really do not want to fiddle with a smaller fuel tank for the "normal" fuel, but, would love the extra milage LPG can offer (with cleaner drive as a bonus )

Anyone seen such a solution with multiple bottles and could point me in a direction towards it?

Cheers,
JapSWede

[Ian Sharpe]

The setup I had for my gen 3 was a tank in the space where the seats folded into the floor. In gen 2 pajero it was under the car with a smaller petrol tank.
Range was always reduced using lpg.

Let me say now that over the years I had 6 vehicles on lpg inc 2 Pajeros , after the last one which was the latest state of the art liquid injection I vowed never to touch the stuff again. There was always an issue with something related to the lpg that cost me money or downtime.
I think that lpg in au anyway has lost its flavour & I don’t see as many people or garages using it now .

Diesel is the go & I wish I had clued in long ago . Better fuel consumption , heaps more torque . But now they are being killed with dpfs & adblue crap & banning or phasing out in EU.

But getting back to your question , on the gen3 & 4 Pajeros the tank can be put in the floor space, but it’s only small tank so range is reduced. I have seen some systems using multiple tanks but you’d be lucky getting one for a pajero , you’d also have to get an installer willing to experiment & customise a kit for you. Big ask.
Whilst gas leaks can happen , they are rare, IMO & all the vehicles I had on lpg the filler was always under the same flap . Hope I didn’t scare you off.��

[mrbitchi]

When installed in the seat well the tank is vented via a pipe to the outside so you wont get LPG leaking into the cabin. I had a 72LT tank in my NM (Gen 3) and when first fitted it gave a range of about 350Ks. After about 5 years for some unknown reason that range dropped to about 300Ks on a tank and never came back.
Of course we still had the normal petrol tank in place so overall the range was over 1000Ks.

To fit that sized tank they actually cut the bottom out of the well and replace it with a dropped version, which means you loose a little rear clearance. I ended up getting a custom bash plate made up to protect the tank.

Overall I had a good run with LPG with no major repairs needed in over 7yrs running it.

[Scrambler]

Don't know that I'd be confident that milage would be better. You burn more LPG than you would petrol. Tanks- these are cylinders so volume rises as the square of the diameter. In short, one big tank is better than a few little ones.

Long and short: if you want more km, get another petrol tank.

If you want to be environmental, get another kind of car (Suzuki Jimny?)

I'm sounding pessimistic, but the key here is understanding the vehicle. It is good for what it is good for. It isn't ever going to be fuel efficient. I'd accept it.

[JapSwede]

Hi all,

Thanks for the responses.

Some additions to better explain my case:

Yeah - the mileage on 'LPG' may not be the same as Diesel, and possibly a little higher than regular fuel, but, the price of the "LPG" is a lot nicer than for the other two. all in all, it becomes cheaper to drive on it as such. I should have used the word "fuel cost per distance" instead of just "fuel per distance"... Sorry!

The thing is also (and this is where I may have misunderstood terms etc) that "our" 'LPG' is that it is made by letting food leftovers etc etc rot and create the gas. This is why the environmentalists are raving about it and even think of govt. subsidised installs on cars being regular or diesel.

Btw - Don't get me wrong - I am all for preserving nature and climate etc, and we do need to reduce carbon foot print, but, not the mindless way - we should do it the smart way and gas created by food leftovers and other leftovers - this I buy in on because it is carbon re-cycle as such. I'd even buy in on the E85 if it's done from forrestry leftovers (which ours is) but, I also see the 'LPG' as a way to extend the combined total distance (like a Auxilary regular tank but, of other fuel type).

Since 'lpg' aftermarket install is not a big thing here (at least not yet - 'lpg' is yet to take off) - there's not much of "bolt on" kits as such at all, hence I think retro-fitting is going to be a "tinker" project for the installer, no matter what.

I'd also prefer not having to remove the second rear row seat. Like to keep it as much "original" as possible. We have a case of govt regulated yearly inspection of the gas system. Most cars built with 'LPG' capability from start, have to remove half of their trunk interior to "free" the tank for the inspection. With the tanks underneath, and a good bash plate covering them, I guess it would be a matter of undoing 4 to 8 bolts and all's visible in an instant.

So, I want to get extended range, cheaper fuel cost, burn re-cycled carbon, without actually modifying away conveniences of the car. I know - it's probably not possible - I guess I am dreaming..

Cheers,
JapSwede.

[erad]

Your dreams are not that far removed from reality. I used to have a NL Pajero (year 2000 model Gen 2) and it ran virtually all the time on LPG. There was very little difference in performance - the car ran beautifully about 95% of the time. Our LPG seems to have less energy per kg than our petrol, and typically the car used 15 to 25% more fuel than petrol. However, at the time, LPG typically cost 40 to 50% less than petrol, so it was a winner. It is 7 years since I sold my NL and bought a NW Pajero (diesel), and in that time, the price of LPG in Australia has almost doubled, so the cost benefits of having LPG have been eroded away. LPG prices vary widely across our nation = they are cheapest in the large cities. I used to work on the formula that if the price of LPG was half that of diesel, LPG was the most economical. Certainly when I switched to a NW diesel Pajero, the driving costs increased substantially, although these days, I think that the diesel would be cheaper than if I still had LPG.

LPG has advantages and disadvantages. Cost is the obvious advantage. The engine runs a lot cleaner with LPG, but if you do a lot of short runs, you can get a bit more acidic buildup in the engine sump oil. Our LPG is a cleaner fuel - fork lifts use it in enclosed spaces whereas a petrol engine would never be used. Because my Pajero was a dual fuel vehicle, I had a small petrol tank fitted under the floor, and a larger LPG bottle fitted where the original petrol tank was mounted. The combination of the two tanks gave me almost double the original range compared to a straight petrol car if I used petrol as well.

Using LPG makes it harder for the spark to jump the gap in the spark plug - the mixture has a higher resistance. Therefore the plug manufacturers used to recommend to close the plug gap up from say 1.1 mm down to 0.9 mm. The higher voltage required to jump the gap also increases electrical stresses on the high tension system - coils and leads. Typically, when it came time to replace the spark plugs the leads would have to be replaced as well, because they would have become brittle. I used to have trouble with cross firing if the leads were touching each other. For example, No 6 plug would be firing whilst No 4 inlet valve may be partially open, and I would get backfires. Big Backfires, because the LPG mixer was mounted roughly in the same place as the throttle valve, so the inlet manifold would be full of air/LPG mix. Typically most LPG vehicles finish up blowing the airflow meter to pieces, and also the air cleaner box as well. I spent a lot of time rebuilding the air cleaner box and the airflow meter.

LPG burns hotter and slower than petrol, despite having a higher octane rating. The effect of this is to possibly raise the engine temperature slightly, but the valves are the components which feel the increased temperatures the most. In Australia, all Pajeros from about the NL model had valves which were rated to be compatible for LPG usage. I assume that models in your area would have been similarly equipped with suitable valves.

It would be advisable to consult with someone in your area who knows more about the specific gas which is available, because our LPG was Liquified Petroleum Gas, ie it was generated as part of the pil refining process, but it was still basically an oil product. Your gas being made from decomposing vegetable products may have different thermal properties. For what it is worth, most LPG mixers seem to have been made in Italy, so maybe the mixers may be universal, but you may need specialised tuning to suit your local gases.

It is possible to mount the LPG bottle inside the vehicle. The valve container on the bottles has provision to fit a 50 mm diameter hose which is then routed to the underside of the vehicle to vent any leaked gases away from inside the vehicle.

[nj swb]

Hi JapSwede,

I think this statement is key to this thread:

[QUOTE=JapSwede;641570The thing is also (and this is where I may have misunderstood terms etc) that "our" 'LPG' is that it is made by letting food leftovers etc etc rot and create the gas. This is why the environmentalists are raving about it and even think of govt. subsidised installs on cars being regular or diesel. [/QUOTE]

Here in Australia LPG is Liquefied Petroleum Gas, a fossil fuel.

Rotting for left overs would be creating Liquefied Natural Gas, aka LNG, or liquefied methane. A different fuel with different characteristics that only had very limited take-up here in Australia.

Issues such as mounting of tanks may have some overlap, but I'll be amazed if any Australian members have run LNG in a Pajero.

[JapSwede]

Hi all,

More responses. I am having a good day today.
Finally I got a confirmation of what I've suspected for quite a while - that what we Swedes are being told to call wehicle gas", is much more split into different areas, in the English speaking parts of the world.
Good to have that sorted. Too bad LPG was not the solution I've should have looked for.

Unfortunately I have a funny feeling that LPG perhaps exists in Sweden too, but, most likely under a different acronym (why would we use the same.... doohh).
The CNG acronym comes to mind. Frustrating that countries can't adhere to same tech acronyms, so we can speak "apples and apples", instead of "apples and pears"...

Ah well. I guess more research is needed on the subject. As usual.

Anyhow - time to return to my "deep refurbish" project on our Pajero. Enjoy the reading in my presentation thread if you're having some time to spare. https://www2.pajeroclub.com.au/forum...ad.php?t=62763

Cheers,
JapSwede

[erad]

Both CNG and LPG will work well on a petrol engine. CNG is basically methane, and methane is lighter than air, so any leakage will rise. LPG is basically propane which is heavier than air, hence the 50 mm drain hose going from the gas bottle covers through the floor of the car to allow leaked gas to escape. CNG requires very high storage pressures to keep the gas in a liquid state. LPG storage pressures are much lower and therefore the storage bottles are made from much thinner steel which is much lighter. Both types of gas are equally good to drive with. About 50 years ago, I was driven around in Iowa (USA) in a CNG powered vehicle, and I had about 30 years in Australia driving my pwn LPG powered vehicles.

[Swede50]

Biogas is quite common in Sverige
Sweden is a leading country in the the uptake of Biogas in passenger vehicles
Should be easy to find out locally.
My Swedish is only conversational these days so hard for me to source you a good link on Google.se.
Did find this as a place to start https://www.energigas.se/fakta-om-gas/biogas/

fordonsgas is the typically complicated/simple Swedish name ,,, LoL

Good luck
Johan

[JapSwede]

Hello,

Ah! More responses = closing in on finishing the puzzle.

Ok. So, Biogas could be CNG and/or LNG then?

I am not sure if Sweden is world leading in anything these days, other than oversimplifying to the extent that things become super-complicated. but, that's probably our specialty - instead of keeping things simple, we over-complicate them...

Many thanks, have a great weekend and Cheers,
JapSWede