tell me about lpg

[omega]

I am thinking about spending about 1000 pounds on a big engine car[maybe a merc or lexus] and getting it converted to lpg.
now there seam to be lots of different makes out there are there any to avoid? is there anything you should watch out for?
are there any downsides to lpg? apart from loseing boot space?
ta

[Kieran]

The cheaper units are open loop, so very basic.

The later units are closed loop, monitoring mixture and correcting it just like efi.

Downsides are weight and boot space as said, that and finding somewhere everywhere you want to fill up, plus stood pressing the filing button on the pump! Slightly less performance and economy compared to petrol.

Positives are running costs after installation and twice as much chance of getting home if one of your 2 fuel systems fail!

[Deleted]

Ignition systems on any LPG'd car will need to be in 1st working order (uprated plugs/leads ect)
Make sure there are filling stations that actually sell lpg in your area.Don't rely on a phone app or google,call the station and ask personally.(don't ask me how I know)
A good set up that is fitted will cost another grand on top of your car.

[dodgerover]

Personally if you are only spending a £1000 i would look around for one ready converted. Unless you are going to cover a lot of miles in a short period or you plan on keeping it for years to payback period is too long.
I like LPG and have had LPG vehicles since the early 90's. A well set up and correctly chosen open or closed loop system can work well on older single point injection or carb'd vehicles.
Otherwise you are looking at a multipoint set up - a decent install with quality components is going to be £1200 upwards.
Just like modern petrol injection systems LPG sysems do need maintenance and as you would imagine multipoint has more things to wear out.

Avoid anyone who says they can do it in a day - you just can't - well you might be physically able to slam it in and make it run in a fashion but thats about all. Ideally speak to other owners of the same vehicle who have had conversions done to get their impressions.
The LPGA bang on about safety and having to have your conversion registered with them, some of the worst conversions I have seen have come with all the appropriate LPGA certification, I've only been asked for a certificate once when getting insurance.

Oh and LPG engined vehicles in my experiance tend to last longer than petrol equivalents - my LPG Combo van had 175k on it and never used a drop of oil between changes, OH's RX300 Lexus is the same - now on 180k

[mdh]

What Dodgerover said. Esp about the lpga.

If you buy a 5 pot Volvo, I have a complete leg injection system.

[ChasR]

I agree with DR until a point. Buy carefully secondhand. Many LPG'd cars I have seen have been a botchwork special, probably down to many jobs taking longer as a result.

As an example, the LPG setup on my Mondeo took around 30 mins longer to change the spark plugs with the LPG kit in the way over it not having it (it's an inlet manifold off job and you can guess where the LPG injectors are attached). Try telling a customer that and see what his mates tell him to do down the pub (you're being ripped off and other such stuff is likely to be said. The fact is that unless you are a patient hands on guy LPG cars are great but with a few drawbacks.

I have never been a fan of mixer systems. Most I have seen run rich (although a BLOS system seems to get around the worst of this) and have backfires.c But some people do seem to make them work or live with the faults for the amount they cost.

Put it this way, even with the V6 Mondeo of doom (not the beige V6) I was the only person to have LPG vehicles last at work ; I (and my dad) must have put on 780k between 4 cars after calculating a few things ; many of the other cars barely did 100k before the owners were sick of the faults or simply tried to live with them (including new cars converted at the factory). If you take the troublesome V6 out of the equation 3 cars still did 618k with only one major issue in that lot (the cylinder head on the 1.8, but I do wonder if that could have been avoided (adjusting the tappets as per the schedule at 100k).

However, when LPG is working right (and with the V6 Mondeo and my dad's 1.8 (bar the valves burning out at 210k despite using an additive) it is great.

[omega]

Mar 23, 2015 0:02:45 GMT dodgerover said:

Personally if you are only spending a £1000 i would look around for one ready converted. Unless you are going to cover a lot of miles in a short period or you plan on keeping it for years to payback period is too long.
I like LPG and have had LPG vehicles since the early 90's. A well set up and correctly chosen open or closed loop system can work well on older single point injection or carb'd vehicles.
Otherwise you are looking at a multipoint set up - a decent install with quality components is going to be £1200 upwards.
Just like modern petrol injection systems LPG sysems do need maintenance and as you would imagine multipoint has more things to wear out.

Avoid anyone who says they can do it in a day - you just can't - well you might be physically able to slam it in and make it run in a fashion but thats about all. Ideally speak to other owners of the same vehicle who have had conversions done to get their impressions.
The LPGA bang on about safety and having to have your conversion registered with them, some of the worst conversions I have seen have come with all the appropriate LPGA certification, I've only been asked for a certificate once when getting insurance.

Oh and LPG engined vehicles in my experiance tend to last longer than petrol equivalents - my LPG Combo van had 175k on it and never used a drop of oil between changes, OH's RX300 Lexus is the same - now on 180k

thanks

lack of boot space is okay checked the fuel and I pass one every day
just been to see a very nice gs300 so things might be moveing
closed/open loop?
so closed is the better system?

[omega]

Mar 23, 2015 1:11:47 GMT ChasR said:

However, when LPG is working right (and with the V6 Mondeo and my dad's 1.8 (bar the valves burning out at 210k despite using an additive) it is great.

so you have to use a additive? didn't know that.what is it called?
why is the filler cap mounted soo low
so the lpg damaged the engine ?

[ChasR]

Damn, this isn't opening a can of worms....

To answer your questions

-It is said that you don't have to use an additive especially with cars (bar J stuff) made around 1990-2003(ish), but IMO I would personally use an additive on anything running on LPG. LPG does tend to run hotter for a variety of reasons (the ignition timing technically being retarted for LPG is one of them) and even compared to unleaded it has zero lubrication properties. A number of modern engines tend to run slightly softer valves and seats so as to aid the warm up times as well. A Jag XJ40 XJR I owned on a single point open loop system was fine after many miles, as was the second Mondeo, and a Laguna 2.0 I converted for a friend years ago.

That said it is a very clean fuel. Almost all of my cars on LPG have always had clearish oil coming out for every oil change, no petrol car of mine has despite how new or old it has been.

-The filler car tends to be mounted low for ease of installation. There is a grey area as to whether it is acceptable for LPGA standards (I.e if you drive off with the filler still attached ; yes, people are that silly!) but for me I like the idea of not creating another rust point and potential leaks inside the boot. A number of cars have the cap installed in the rear quarterpanel with some having the fillers next to the petrol filler cap!

-Yes and no. My V6 did 265k before it got written off by somebody and we converted it to LPG (on a multipoint system) at 120k. The compression at the last spark plug change was spot on as well. I did stick to running that on Flashlube though.

However, my sister's Mondeo required another head at 170k as the valves burned out ; that was converted at 100k. It was the same for the 1.8 my dad had but again that had done 80k's worth of hard mileage, and in both cases I wonder if reshimming the tappets when required could have prevented it. My dad's car is now on 295k since the head rebuild at 210k and it is still going strong.

OTOH, a BMW 520i 2.2i at work had no end of issues despite being professionally installed. It pitted all of the cylinder head valves after 70ks worth of use.

Likewise, my dad's 2.5 Mondeo V6 which was installed with some of the best kit from a well known Leicester specialist gave us no end of grief. Granted we did drive the car hard, but in hindsight if I had spotted a few things sooner I would have never have committed to that car as I did.

Can LPG work on cars? Yes, but the engine and generally the parts attached (cooling system, ignition system etc.) MUST being in near perfect condition and remain so after the conversion. When on song the benefits are hard to ignore and truth be told I doubt a modern diesel could have got to the mileage either the V6 Mondeo or the 1.8 did without ALOT more cash thrown at it.

I am not trying to put you off, but merely sharing my experience after playing about with them myself and see just how badly it can go wrong for those who thing 'that leaky hose will be fine', I'll ignore that misfire etc. . Before anyone accuses me of fearing about nuns and kittens as they all love to I have aided in converted 3-4 cars to LPG on multipoint systems (and a couple years ago to single point) and have generally helped others out, so it is not like I am merely scaremongering.

IMO it all comes down to how many miles you expect to put onto the car.

[richrolls]

I run a C-Max 1.8 with Multi point LPG. A OVML system. It has done a hard 100k miles since conversion. I've done 25k with it in my ownership. It has been faultless lpg wise.
LPG halves your running costs. Simple as that. Think miles per £ pound you put in the tank, don't get hung up on mpg on gas etc etc.
Buying one converted, just use normal buying used car common sense. There are brilliant forums and lpg people out there. Anyone who knocks it doesn't understand it or has had a badly set up/maintained vehicle. There is no reason for an internal combustion engine to run poo on an explosive gas.
A few LPG specialists out there only work on certain systems. Don't know why, and therefore will promote those systems and vice versa. But by and large I have found everyone involved in the lpg world very helpful.
Fill Lpg is an app I use. I have found it very reliable. It is updated by sad acts like me with daily prices and recommendations. I cannot comment on others as i haven't used them. Miles per pound, it is unbeatable.

[dodgerover]

Mar 23, 2015 18:31:36 GMT omega said:

day
just been to see a very nice gs300 so things might be moveing
closed/open loop?
so closed is the better system?

Closed loop will adjust the mixture on the fly to be closer to Lambda, I'm not up on the GS300 but I would say it should probably be running a multipoint system, the OH's Lexus also runs with a posh digital version of the Flashlube additive system, no idea if it really needs it or not as it was fitted when we got it, it uses very little additive so we just keep it topped up.

You can put the filler point wherever you want (within reason - you can't have it inside the car for example) however most people tend to hide them away slightly.

If you haven't had an LPG vehicle before DO NOT put your foot on the throttle when starting (especially if starting on gas) as you will increase the chances of a backfire, catching it on the throttle when it fires is fine.

[gostin]

I had lpg on my 2005 x5 4.4 and it was fantastic.
Went from £110 per tank and 350 miles to £38 per tank and 250ish miles.
Got the big bus cheap as no one wanted a 4.4 paid 2k for the conversion and it still came in a lot cheaper than buying the diesel from the same year with same spec and mileage.

[heathrobinson]

A mate got an A8 with LPG on for about 1400 notes, and drove it for a few years before selling it on for the same amount. He had about 6/7 cars for most of that time, and the A8 was generally the cheapest for long journeys.
I had open-loop on my v8 landy for years, the simplicity was in keeping, and it made the truck affordable to keep.
Have a look at the stuff about BLOS carbs though, again very simple, but tuneable to a shade off the most complicated ECU'd multipoint jobs.

[omega]

done a lot of reading now
my worries are valve damage and lubrication some people are saying use Flashlupe some say this can also cause problems [not enough or to much] somepeople are also using redex.