Ls430 On Lpg

Haylands · February 9, 2008

Hi all

Circumstance have now changed (mileage travelled/cost of petrol) and I have decided to fit LPG to the LS430, if you read below from an earlier post of mine you will see that I wasn't going to fit LPG on grounds of reliability, well I'm now going to fit a Prins VSI fully sequential injection system with spare wheel mounted tank. I will do the install myself at a registered LPGA approved installers premises and it will be certified by him on completion.....

Now the question is would anyone like me to photograph the install and create a topic on here showing what’s involved, or are you just interested in the savings...???

Let me know your thoughts

Cheers

Pete

I worked for a LPGA approved garage for about 18mths fitting single point and multi point on all sorts of cars from a 3 cylinder Matiz to a 12 cylinder Jag and just about everything in between....

I do not know everything about lpg and others on here may know a lot more, from my limited experience and a general interest I have found out / noted the following, I'm putting it on here to help others make the decision...... lpg or not????

A few Facts about LPG

It has a lower calorific value than petrol but an octane rating of about 110

It burns hotter than petrol

It produces no acid in the ignition process

It will give you better emissions then petrol (if set up correctly)

An Lpg tank is virtually impossible to damage enough to cause an explosion, a controlled release and ignition into a flamethrower yes, but the pressure in the tank is too great to allow oxygen back inside to create an explosion

Now there are two basic types of installation,

Single point

Multi point or injection

Both systems introduce Lpg in its gas state into the engine instead of petrol (Ford tried with a liquid LPG injection system but it didn't work very well)

The basic or single point system involves a tank with a pipe to a vaporiser which turns the liquid Lpg into gas, this is then fed to a mixer which lets the gas into the engine, with this the amount of lpg let into the engine is controlled by a stepper motor in a closed loop system, this takes a reading from the lambda sensor and then adjusts the mixture accordingly, this is the type most commonly used (there is a system for early cars with no Lambda but they are few and far between now)

Multi point injection system, uses a tank and pipe to a vaporiser which then feeds gas to an injector for each cylinder, this is controlled by a separate ECU that "steals" info from the cars ECU, adjusts the gas injector opening time accordingly (you need the injector open for longer to get more gas in than petrol because of the reduction in calorific value). The system also monitors the Lambdas and adjusts the mixture with them as well.

A properly set up injection system will have no reduction in power over petrol but will use approx 15-20% more Lpg than petrol, the emissions will be better with less C02 being released, indeed you could even remove the cats and still pass the latest emission tests (but this is not allowed).

Most Injection systems start on petrol then swap over to Lpg after a short time, this is usually done at a certain temperature

Contrary to popular myth this has nothing to do with a car not working on lpg when cold, this stems from early systems with poor vaporisers that could not vaporise the lpg unless they were very hot, I ran a Range Rover V8 for several years that ONLY used LPG, it started on LPG at -10c with no problems....

The reason the systems start on petrol is to give the petrol system something to do, the early days saw cars run for 1000's of miles just on lpg, then the driver ran out and switched over to petrol only to find nothing happened as the petrol system had stayed dormant for so long it was all seized up!!!!

Now most injection systems that are SET UP PROPERLY will not have much of a detrimental effect on engines

Most single point systems will damage an engine unless they are set up right.

I saw lots of single point systems on cars where they had been set very rich to get the system to run because of badly matched parts, the vaporiser has to be big enough to cope with the demands of the engine.... ie the bigger the engine, the bigger the vaporiser that is needed, the mixer is very critical to each engine as well. It is easy to get a car to run on lpg, the trick is to get it to run right.

Most cheap single point systems will work but they will flood lpg into the engine and cause a rich mixture, this creates excess emissions and will damage the engine. If you have a single point system get the emissions checked, this will give a good indication of the quality of system/installation. Interestingly a friend who has an MOT garage always checks emissions on duel fuel cars on petrol because "they all run rich on LPG don't they"

Lpg, being gas, is a dry mixture and does very little lubrication, I would always have a Flash Lube system fitted as it can't do any harm (just check it gives 5 drops per minute at tick over with a warm engine)

Lpg does not like running with platinum spark plugs, it can give misfires, although I did run a Voyager 3.3 with platinum plugs for 15000 miles with no problems....

The engine oil does not get very dirty when running on LPG as there are minimal acids and other nasties from the combustion process, this does not mean you can change the oil less, it is still getting bashed to bits by the engine and wears out just as quick, it just stays looking better.....

So go for it if you do loads of miles but make sure you get a well matched, well installed system especially if it is single point...

Oh and before anyone asks no I haven't got it on my LS430 I know what’s involved in fitting it and I know how many original wires are cut and spliced and I don't want to reduce the reliability of my car..... most engine running faults on cars with LPG are down to ingress of water or wires chaffing from the original install and I bought a Lexus because I wanted reliability as well as a nice car....

Pete

eXOBeX · February 10, 2008

Well worth doing a step-by-step of the install, methinks. Even if nobody'd dare try it themselves, it'd be interesting to see. For those who are already gassed-up, it'd be interesting to see what the mechanic got up to.

If your wheel well currently has a plastic tool tray/oil catcher thingy under the carpet (the Mk.2 GS does) cutting out the oil catcher section with a jigsaw makes it fit snugly around the tank, and the carpet sits back on top nicely.

Oh, and you missed out one more point about LPG... 50 pence per litre!

steve-bedford · February 10, 2008

Documenting this is an excellent idea Pete. I'm sure lots of peole will benefit as the LS430 gets older and into the territory for more DIY.

Slighly off topic, but very related. I've always driven big engined / thirsty cars and done a reasonable mileage. I've never ever managed to get the LPG business case to stack up for me though. i.e. I would just never break even, let alone get any pay back. I would be as intrigued to see your calculations in case I'm missing something although I'm guessing you have connections that mean your installation costs are much lower than the norm. My other nagging concern is that ever since the government lost interest in LPG, I do wonder how interested the oil companies will be in bringing LPG to the forecourts in another 2 / 5 / 10 years time. A crystall ball would be nice wouldn't it?!

Haylands · February 10, 2008

Documenting this is an excellent idea Pete. I'm sure lots of peole will benefit as the LS430 gets older and into the territory for more DIY.
Slighly off topic, but very related. I've always driven big engined / thirsty cars and done a reasonable mileage. I've never ever managed to get the LPG business case to stack up for me though. i.e. I would just never break even, let alone get any pay back. I would be as intrigued to see your calculations in case I'm missing something although I'm guessing you have connections that mean your installation costs are much lower than the norm. My other nagging concern is that ever since the government lost interest in LPG, I do wonder how interested the oil companies will be in bringing LPG to the forecourts in another 2 / 5 / 10 years time. A crystall ball would be nice wouldn't it?!

Steve

Mileage 10000 a year

Average Mpg over last 5000 miles for me was 22

Petrol cost 109p per ltr

LPG cost 50p per ltr (max)

That's 2066 ltrs of petrol a year at a cost of £2252

Or 2582 ltrs of LPG (you use about 20% more) a year at a cost of £1291

That’s a yearly saving of £960

Or another way 23p per mile on petrol and 13p per mile on LPG

That’s 10p per mile cheaper and an equivalent mpg of 39

Your car will be worth a minimum of £500 more at resale, probably nearer £1000 for the top of the range kit

It would cost YOU less than £2000 for the kit fully installed

So take £750 as an increase in car value so you have to save £1250 before breakeven

That’s 12500miles

There are more and more garages selling lpg, if the demand is there then they will keep selling it, all our local police force vehicles have been converted to run on it and many bus companies are using it as well

There is also a large increase in the number of LGV's being converted to run on lpg as well as diesel, about a 20% mix and you either gain power or economy.

So the demand will only increase the supply will match it after all the oil companies just used to burn it off as a waste product now they can sell it....

The government have promised to keep the duty at its present rate for a rolling three years so the cost should stay low until well after you reach payback

So..... watch my thread which will be started soon and then you can fit it yourself and save even more!!!

Pete

Boxbrownie · February 11, 2008

Pete, I would be most interested to see the install......wish I was located closer, I'd take the piccies for you! I have an RX just purchased '03 Mk1 and am seriously on the cusp of booking it in for conversion. The way I see it presently is the sooner the better for the conversion and beginning of payback.....I worked out between 20>23 months payback without the selling on bonus. I aim to keep the car up to 3 years, so will be well in pocket at sale time and as you say the government have pledged to keep LPG at the present level in relation to petrol until 2010 I beleive.....

I think this would be an excellent article and most useful even to those merely interested rather than seriously going for the conversion....

Best regards David

Chris Skelton · February 11, 2008

Very tempting prospect! Will watch with interest.

does anyone know if France/Spain etc set up with good supplies of LPG too?

Haylands · February 11, 2008

Boxbrownie,

Thanks for the offer but even my nokia n73 is better than your box brownie!!!!!

Chris Skelton

LPG is known as GPL in France and GLP in Spain and Portugal

It is widely available in France and is getting much better in Spain with more and more stations, it’s about the same price as over here.

You need an adapter to attach the filler nozzle to the car with the French pumps... About £15, but I believe the Spanish are using the UK/Dutch bayonet fitting.

There are overlays available for various aftermarket satnavs that show garage locations in the UK and across Europe, do a Google to find them, they tend to be free.

Will be seeing my mate at the garage tomorrow and sorting out a date to fit it so will let you know soon.....

Any more questions or suggestions please ask

Pete

LexAzur · February 11, 2008

Hi Pete

Good system to pick I have the same system on my 2001 GS430 and have had no problems with it, it was installed 19/12/2005.

I also fitted the same to my 1992 GS 300 I had and again no problems and it is still going strong.

On the GS430 the type of tank fitted was a Toroidalny with a capacity of 77 litres which means you can get approx 60-63 litres from complete empty on a refill. My tank is located in the spare wheel space.

LexAzur · February 11, 2008

Hi Chris

In France 99% of all petrol stations on the pay motorways have LPG but it's called GPL over here.

About 1 in 3 garages in the towns etc have GPL.

The price at the moment ranges from 0.69 cent/litre to 0.77 cent/litre off the pay motorways and from 0.77 cent/litre to 0.88 cent/litre on the motorways, this is the highest I have seen lately. I filled up for 0.69 cent/litre yesterday.

Spain, NO CHANCE only petrol and diesel in those stations.

Hope this helps Chris

Very tempting prospect! Will watch with interest.
does anyone know if France/Spain etc set up with good supplies of LPG too?

eXOBeX · February 12, 2008

Don't forget though, if you've got LPG you can't take the car through the Channel Tunnel, you've got to take the ferry.

Haylands · February 12, 2008

Right... Car is booked in for me to do it on 27th February, have taken a filler to the paint shop to get it painted in the car colour and had a play with some tanks...

Looks like I'm going to use a 68ltr four hole full toroidal tank, you can fit a slightly larger single hole tank but these are slow to fill compared to the four hole tank that fills at about the same speed as most petrol pumps.

There has to be a 20% space in the tank for expansion so it will give a fill of around 54-55 ltrs which will give a range of about 220 miles.

I will start a new thread with pics when work begins

Pete

newbie · February 22, 2008

GUYS.

Just another thing that you should be aware of.

Most bigger Asda stores sell LPG. Go and get yourselves an Asda credit card and use it solely as a fuel card paying off the balance each month.

As well as my trusty MK3 LS400 (petrol) I also run a 4.6 rangerover as my everyday car converted to LPG, and I notice a very slight decrease in power when running on LPG, but certainly nothing that out weighs the cost savings.

Anyhow I digress, the deal is 2p / litre off every litre purchased using the credit card (petrol / LPG or Diesel)

The amount of miles I do each month gives me a monthly saving of approx £12-15 / month, which over the year is anywhere between £144-160, as they say.....every little helps and it's completely free if you pay the balance off every month !

So yes you can get something for nothing !

Haylands · February 24, 2008

Hi all

The LPG install has had to be put back as I have to wait for the repairs to the back... see other thread Lexus v Discovery

They will have to repair/replace the rear panel so I'm leaving out the tank untill after the repairs

I may fit the front end out before, will have to see how it goes

Pete

Boxbrownie · February 24, 2008

Would be nice if ASDA down here sold LPG....its my local station and always the cheapest for splash around here......but no LPG for sure! There are a few but virtually all BP and quite pricey....still want to do the conversion though.....

Best regards David

eXOBeX · February 24, 2008

In South Wales at least, a lot of Morrisons stores sell LPG. Swansea, Ebbw Vale and Barry do. Brecon don't and I don't think the new Llanelli one does either, I don't know if the Risca one does fuel at all.