LPG installation

Tattysnuc

Tattysnuc

Tattysnuc

Associate
Joined
22 Sep 2008
Posts
1,493
Location
Liverpool
Hi folks,

Apologies if this has been covered elsewhere, but I had a quick search, and nothing obvious sprung up.

With the fule prices beign so high, I'm seriously considering the cost of an LPG converstion, but I know very little about them

I believe they need a pressurised cannister to be mounted somewhere inside the car....?
How much do they cost to install? Is it a lengthy process? Good experiences/Bad experiences with installations?
Is every car convertible?
If not, why not?
What effect does it have on the MOT test? Do you have to notify DVLA?
How do you fill the LPG tank?
How big are they?
Are they any less efficient in a £/mile ratio - we havea Rover 75 '54 plate, and it guzzles the petrol compared to our old car (peugeot 106) No longer 12 p/mile more like 25p
How do you switch from one fuel source to another, assuming that both remain?

Can someone lend me the wealth of their experience with this as I'm genuinely interested and would like to know more.

Many thanks

LPG Virgin
Tatty
 
Yes you need an additional fuel tank, common place is where the spare wheel goes and that can hold about 45litres.

I believe for a good multipoint conversion you're looking anything over 1500quid depending on the car etc.

Most petrol cars can be done but some do have issues, the ford mondeo ST220 engine i beleive had some issues as running on LPG they do tend to run hotter or something. I have a friend who had a singlepoint conversion done in a 1.3 fiesta and that ended up killing the engine after about 40k due to the increased heat.

You have to notify the DVLA and insurance, MOT is fine i beleive aslong as its been installed correctly, you also get *slightly* reduced road tax, by about 15quid i believe.

You need another hole somewhere in the car to fill it up.

they can be between 40 to about 80 litres when i looked them up a while ago.

they tend to be less efficient running on LPG as the fuel has a lower calorific content than petrol so you need more to get the same power, so say you get 30mpg on petrol it might be 26 on LPG.

The systems will auto switch, it always starts on petrol until the engine is warm then auto swaps over. Some of the fancier systems will swap back to petrol when you go full throttle during an overtake for example.
 
There is a fair few factory fitted dualfuel Volvo's about as well.

Im currently running a v40 dualfuel as a workhorse, 220k miles and still going strong.
 
Last edited:
Personally I would sell what you've got and buy a car with the LPG system already fitted.
Try and get one with a sequential multipiont system rather than a mixer single point.
 
never forget that post at FocusST owners club forum, guy got his ST225 LPG'd it didn't last long before it went wrong, burnt the pistons or something, needed most of a new engine lol
 
MrMoonX said:
never forget that post at FocusST owners club forum, guy got his ST225 LPG'd it didn't last long before it went wrong, burnt the pistons or something, needed most of a new engine lol
Click to expand...

Thats the liners that go, mainly on pre 2008 cars though i believe.
 
Thanks for all the feedback folks - there's certainly a lot in there to research. I was rather hoping it would be a simple case of plug and go, but I'm now having second thoughts. Selling the car is not really an option - we just had to spend a grand on a new clutch, dual mass flywheel, gear selectors etc so I was looking at a way to try and cut the running costs, and this looked like the "lowest hanging fruit." Think I'll give it a miss for now.
 
I believe they need a pressurised cannister to be mounted somewhere inside the car....?

Yes, as mentioned either in the spare wheel position or taking up boot space

How much do they cost to install? Is it a lengthy process? Good experiences/Bad experiences with installations?

Go with a reputable installer and it should be a good experience, it will take at least a day to install

Is every car convertible? All petrol cars can be converted, whether this is a good idea or not is a different matter.
If not, why not?
What effect does it have on the MOT test? Do you have to notify DVLA?

At present there is nothing special in the MOT for LPG converted vehicles, they are tested on the fuel they are presented running. DVLA do not need to be informed but your insurance company will

How do you fill the LPG tank?

At a petrol station that sells LPG at the pump. Connect filler, push button, fill.
How big are they?



Are they any less efficient in a £/mile ratio - we havea Rover 75 '54 plate, and it guzzles the petrol compared to our old car (peugeot 106) No longer 12 p/mile more like 25p
How do you switch from one fuel source to another, assuming that both remain?

There will be a switch on the dash, design and function differ between conversions. Most have a simple LED gauge to give you a rough idea of LPG remaining.


It's also worth doing a rough calculation based on your current MPG, predicted MPG on LPG, cost of conversion and current annual mileage.

Much like a diesel, there's a point where it becomes worth while running on LPG. Before that point you will never see a return on investment.

If you plan to keep the car for 5 years, it's in good overall condition (ignition MUST be 100% prior to conversion) and you do the mileage to justify it, get it done.

I've been running Range Rovers and Land Rovers on LPG for the past 7 years, I'm struggling to think of any issues that can be attributed to the LPG conversion.

LPG has saved my bacon when the petrol pump decided to pack up on my Disco. They don't like starting on LPG in -5 though :/
 
Tattysnuc said:
Are they any less efficient in a £/mile ratio - we havea Rover 75 '54 plate, and it guzzles the petrol compared to our old car (peugeot 106) No longer 12 p/mile more like 25p.
Click to expand...

No they are more efficient on a £/mile basis, however they are less efficient in a MPG basis (usually ~80%) so if your car did ~25mpg on petrol it will only do ~20 mpg on LPG, however as LPG is much cheaper than petrol it equates to ~38 equivalent mpg (on the basis that you spent as much on LPG as you would have on X gallons of petrol and it did Y miles per a gallon of the imaginary petrol).


taske said:
At present there is nothing special in the MOT for LPG converted vehicles, they are tested on the fuel they are presented running. DVLA do not need to be informed but your insurance company will
Click to expand...

Yes there is, LPG vehicles take the "non cat" emissions test usually reserved for cars made before late 1992.



Don't forget when you go LPG your saving the environment as well as your wallet, :P
 
Tatty;

I'm running a E46 330ci at the moment on LPG, and my previous car also ran on LPG which i had converted myself whilst i was at uni.

Although its given me years of cheap motoring, I would not recommend it unless you are doing mega miles.

If you are still considering it after all the above posts try to consider:
A: The cost of install vs the payback period.
B: Make sure you consider that you may have to drive further to get to a LPG station.
C: LPG MPG will be lower than on petrol. 20% is a good figure for this.
D: If it fails later in the cars life, there will be costs associated for the repair of the LPG system.


I'm in plymouth and its no longer practical to use LPG as I have to drive out of town 5 miles to top up, and it has got expensive as its the only garage around.

Dont worry too much about engine damage, a properly converted engine will be fine. Some manufacturers offer a guarantee against damage to the engine caused by LPG burning at a higher temperature (causing valve damage). Although some engines are not suitable for conversion - most engines are. Your LPG installer can check this.
 
ubersonic said:
Yes there is, LPG vehicles take the "non cat" emissions test usually reserved for cars made before late 1992.
Click to expand...

If you wish to be pedantic, then yes, but to the average person this makes little difference. LPG also burns a lot cleaner than petrol so passing the emissions test is hardly a difficult prospect :)

Worth noting though, if you take a vehicle fitted with LPG to a MOT station whilst it's running on petrol it will be a standard petrol test. Take it on LPG and it will be tested as you stated.
 
I'm just going to add couple notes. LPG systems need servicing, so if you want to do things by the book, it will be additional £60-80 cost every 12k miles or 12 months.

In a genuinely facepalm worthy decision, British LPG systems have different filling socket to the rest of Europe (Netherlands excluded), so if you travel to the continent you will need set of clunky adapters.
 
Only thing I have been advised is that with the heat and the fact that oil and lpg don't react is it can shorten spark plug life over petrol, but they arent exactly a costly part to replace if there are issues.

Also notice on mine that the engine temp does increase if im stuck in traffic for long periods of time. That could just be a limitation/issue with my cars cooling rather than a general side effect though.
 
Bump.

I now find myself having my Monaro as a daily driver doing around 20,000 a year. Obviously taxing, MOT'ing and insuring a second smaller car will wipe out the fuel cost savings. So now I'm thinking about an LPG conversion. Are there any draw backs to this? I know you get a small reduction in power and economy but I'd be saving clost to £2500 a year based of current fuel prices. I've read about exhaust valve seals failing due to extra head and lack of lubrication, is this a concern these days?

A last resort before I sell up for a hot hatch.
 
Princey said:
Bump.

I now find myself having my Monaro as a daily driver doing around 20,000 a year. Obviously taxing, MOT'ing and insuring a second smaller car will wipe out the fuel cost savings. So now I'm thinking about an LPG conversion. Are there any draw backs to this? I know you get a small reduction in power and economy but I'd be saving clost to £2500 a year based of current fuel prices. I've read about exhaust valve seals failing due to extra head and lack of lubrication, is this a concern these days?

A last resort before I sell up for a hot hatch.
Click to expand...

You can get a lube injection system to coutneract this or run part gas part fuel perhaps?
 
You must log in or register to reply here.
Back
Top Bottom