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Discussion Starter · #1 ·
Hello All,
It's a wet bank holiday and fun in the sun has been put on hold so I thought I would spend half an hour showing you my LPG powered 1.2 Aveo S A/C.

The car was bought as a post divorce poverty car to enable me to keep claiming my £4k/year car allowance from work, 6k on the clock, 9 months old, £5499, from Wilsons of Sc**thorpe. Ran it for a year, put 12k on the clock, paid myself back about £8k and car was faultless, and comfortable too. Christened the "Spaz Chariot" at work it was popular with my kids too. Then things changed a bit, work wise, and the chariot went into storage for 18 months. Roll the clock forward, another 8k on the clock, another £4k in the bank, and it's time for a new car, right? Wrong! It's time to experiment.

The car has had no problems and suits my purpose well, so I decided to keep it. Coupled with a 5 month contract requiring some 700miles/week, I looked into an LPG conversion.

I am a well experienced amateur mechanic, having been keeping my cars alive, building kit cars, and resurrecting hopeless cases for over 30 years, but have no experience at all of LPG.

Based on convenience, price and a casual look round their place, I let autogaspol do the job for £650 (I paid an extra £35 for a concealed filler as we shall see later). The job took from 08:30 until 16:00 on a Saturday, so about 7 hrs working time.

You can see a list of parts very similar to those used in the conversion, at autogas-lpg.



The price being £430. Hence in very rough terms, Autogaspol are charging £220 for 7hrs labour/skill/facilities/overheads. Very reasonable.


Specifics

Tank



The tank fitted is a 41 Litre Stako toroidal tank in the spare wheel well, along with the multivalve assembly. A 41 Litre gas tank will hold a maximum of 80% of it's capacity in terms of liquid gas, to allow for expansion pressure, hence theoretical volume is around 31 litres. In real terms, full-empty capacity is about 29 Litres (roughly 6.5 gallons), which, as we shall see later, equates to 200-225 mile range on LPG. There is just enough room to keep the jack, wrench, etc down the side of the tank.

Reducer/Evaporator

The car is fitted with a steffanelli reducer, to take the liquid gas to gas phase for the injectors. It is heated by being plumbed into the cooling system by means of branches on the feeds to the heater matrix. A temperature sensor connected to the ECU allows control of the gas valve, and the gas injector rail, as well as turning off the petrol injectors at the appropriate time. From a cold start on a frosty morning, the Aveo needs 2 miles to get up to temperature for gas operation, if the engine is under load at the time there is a faint "bump" on switchover, if on overrun it is not perceptible. Subsequent starts are almost instantly gas. If the car is left all day after a run, it needs about a mile to get up to temperature.

Injectors

These are standard OMVL sequential gas injectors. Autogaspol left them "loose" on top of the spark plug cover, which looked inelegant to me, so I made a little bracket up. They feed gas to the engine via tubes tapped into the plastic manifold, and sit adjacent to the petrol injectors.

ECU

This is a PRIME sequential controller, wired in to use the existing sensors, etc. The cabin control is wired in too. This allows manual switchover to petrol if required. It also has a 4-LED gas level meter, which as any LPG driver will tell you, is as much use as **** on a boar pig, the only way to know how much gas is left is the trip counter.





Filler

I've opted for the "discrete" filler hidden behind the petrol flap, rather than the big plastic one. This causes no end of anger at Morrisons, because they always put the gas pumps in the middle, and fists get waved because I don't move forward.
The adapter to full size is hanging on the cover.



Costs

Firstly, although LPG is less than half the price of petrol at time of writing, you DO NOT make a 50% saving. LPG is around 15% less potent than petrol, and YOU WILL lose 15% of your economy. I have historic data for my car, and it uses almost exactly 15% more gas than petrol. My daily commute is 130 miles and I consistently use 16 Ltrs of gas, (3.5 gallons, 37 mpg). Hence my running cost is around 7p/mile. My best estimate is of a payback mileage of between 13 and 15000 miles.

Downsides

You lose the space taken up by the spare wheel. In my case this is utterly irrelevant as the car has only myself and my dinner in it for over 90% of it's usage. You need to use LPG spark plugs to avoid misfires, and these cost £62 a set, rather than £16 for the normal ones. You need to fill up much more often, and annoy people when you do. People think you are a nutter/geriatric (but then they do anyway if you drive a T250/T255-for record I am a nutter so no big deal). You lose 15% of your power at max revs, so don't try racing M3's at the lights. You may limit your market for reselling the car. There are still myths out there about "bombs in the boot" etc which although nonsense do affect some people. My daughter (who will be 17 next year) is already showing a lot of interest in the Aveo though, wonder why....

Autogaspol- Disclaimer

This article should not be seen as a recommendation or criticism of Autogaspol. I picked them at random and they did a reasonable job that has caused me no problems and appears to have been properly done. I would be happy to use them again, but others may not be. They are a company run by Polish nationals and there may be the odd language problem. If you have a problem with Polish people working in the UK, then steer clear (I don't, 30% of the population of my town is Polish, <strike>and the girls are nicer than the locals</strike>). Poland is the third largest user of LPG vehicles in the world, so maybe they know a thing or two about them?

Comments/Questions

Are very welcome, fire away, but remember that I had this conversion done for "fun" out of curiosity, so telling me I must be mad will cut no ice.
 

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i know this post is dead but thank you for this accurate post...my brother in law will love this article... he always wants to corrupt me by trying LPG on my Aveo.. Many thanks
 

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T250 2dr. 1.2 lpg
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Discussion Starter · #4 ·
Alecs,
The post was dormant rather than dead, I guess there aren't that many Aveos running on gas out there. Or other 4 cylinder Chevys for that matter...

The car is still owned by me, and still in use, but was retired off from work use a few weeks ago at 76,000 miles, having earned me enough to buy a lovely, expensively optioned, 16 plate 508 2.0 diesel GTline saloon.

My daughter went on to learn to drive in the Aveo, and did over 1000 miles in it in her first 3 weeks on the road. She doesn't want the spazzer though, my ex has bought her a 12 plate 208
.

I've had a few issues related to using gas, but nothing really taxing. Sparkplugs don't last very well. 20k really is your lot. After 25k of use, the injectors were gummed up with what is known as "heavy ends" (thick oil contamination of the lpg from the refinery), but it took quite a bit of figuring out, solved eventually with help from a Land Rover user who has had the same trouble with his OMVL injectors. Thankfully the fix was easy, a quick few minutes strip down and a wash of the components in a jar of petrol.


Not long after the conversion, I'd obtained the software, and made up my own diagnostics cable. This was handy as occasionally the engine cut out as you dipped the clutch at a junction after a fast approach. Apparently under some overun conditions the gas injectors don't open properly due to the vacuum. This is a known problem and fixed by ticking a box in the software to tell the system to turn on the petrol injectors for a few fractions of a second-which works perfectly and seamlessly.

The reducer fitted turned out to be a bit rare in this country, and the liquid phase filters difficult (read impossible) to get. But this is the 21st century, and replacements from Latvia only take a few days...

The car has been home serviced only from 20k onwards, and the oil is always very clean when it comes out. The petrol filter was changed recently because although it burns very little petrol, the fuel pump is always on and thus the tank contents is constantly recirculated. I took to only carrying about 10 ltrs of petrol, and topping up when it got to about 5 ltrs, once a month or so mostly because of the weight. The weight issue was that with the heavy lpg tank in the boot (25kg empty), plus fuel, and the spare wheel, and other stuff, the car did ride a bit "nose up". So most of the time the petrol tank was kept low, and the spare wheel trapped behind the drivers seat.

Even though I now have a bigger "better" car, getting back in the Aveo reminds me of how comfortable it actually is. Last year I took a few trips into Europe in it. I can just get into Belgium from home on a full lpg tank and when you get there, lpg can be had for 24p a litre


Also, the car is London congestion charge exempt.....

When I had the conversion done, I knew that I would be doing 30k in the year, so payback was only 4 months or so, I've learned about lpg along the way, and even considered a Dacia Logan MCV as a replacement. The Aveo was sold in several markets running on LPG from the factory, so I knew it was a safe bet. In the end I just fancied (another) big Peugeot saloon (I'm a repeat offender
).

But for now, the Spaz Chariot rides on......and it had it's summer wheels put back on the other day, all nicely painted...and a wash and polish...so maybe time for a photo shoot?







Edited by: Metro1000
 

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T250 2dr. 1.2 lpg
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Discussion Starter · #5 ·
Well, to revive a dead thread again, today I changed the Aveo's spark plugs after a bit of poor running recently, and did a bit of preparation for the fitting of some new gas injectors in the new year. I took the opportunity to put the boroscope camera down the bores to see how things were looking. So if anybody wondered what the piston crowns of an 85,000 Aveo thats been running on gas all it's life (and to be honest who hasn't wondered what it looks like inside their engine). If I manage to find the mirror adapter for the camera, I shall take some upward shots and have a look at the valves..... It has of course got 4 pistons, but some of the gas equipment makes it tricky to get down nr 2 and take a picture, so 1,3 and 4 only...
 

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Hi Metro,

Interesting pics. Is the light grey colour just a light combustion coating on the metal, or the natural alloy?

I'd be interested to see what the inside of the bore on a typical diesel engine might look like if you ever get the chance.
 

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Discussion Starter · #7 ·
Ed,
As far as I could see (By looking down the holes with a torch), that is the natural alloy, the very faint marks near the centre being the combustion marks, since it has run on LPG nearly all of it's life carbon build up is unlikely. I've read that converting engines later in their life can be bad because all the build up around the rings burns off and can cause compression loss. Unfortunately I could not find the mirror adapter for the camera the other day, I really wanted to have a look upwards at the valves (I don't think there is anything wrong, just curious-best way to be I reckon), but when I find it I will have a look when the new injectors get fitted (the OMVL injectors work still but are showing their age, and I obtained some much better MTM [BRC] very cheaply not long ago, just waiting for some adapters for the wiring to arrive).

The only old diesel I have is the 407, which I've had from new (now at 105k), and it has been 100% reliable thus far, so never needed to do any any engine work apart from 10k oil changes and the filters, but will have a look if the chance arises.

It's off topic but the Peugeots both use Cerium based Eolys fluid to help increase the exhaust temperature to burn off particulates in the DPF, doses at the rate of 15ml/full tank of 70 litres. I had the diagnostics on it last week and it still has 1600ml left (so 60k+), never had a warning and the system is totally "silent" in operation, no lights, no excessive fuel burn ever. I look on the DPF problems of GM stuff with dismay, can't help but think it was cheapskating that has done it, and probably has, and will, bring about the unnecessary early demise of many vehicles.
 

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Thanks for posting. Very informative. I recently bought a Chevy Aveo 2011 LPG model in Thailand for office commute. For some reason, the car consumes some amount of petrol even if it runs on LPG mode. The LPG switch is always ON. However, the fuel indicator for petrol shows the amount of fuel getting lesser over weeks. Not sure what is the problem. The worst thing is that Chevrolet closed their production and services in Thailand last year. Has anyone else experienced similar problem with their Aveo LPG/CNG?
 

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I dont think there is any problem with your vehicle using some petrol. This is usual. The following extract taken from the internet says "You do still need to have petrol in your tank too, the system works at the optimum temperature so you can't start and run purely on LPG. Petrol is also required now and then in the combustion process, using roughly 1/5th of a tank of petrol per full tank of LPG. "
I believe Member Metro explained this two/three years ago.

As a new Forum Member the following link has some helpful information about the Forum. Please remember to complete the two sections you left 'blank' ie your World location and the vehicle detail section. This information will then automatically appear every time you post and assists members/readers, as well as avoiding you having to repeat it every time. Thanks.
 

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Discussion Starter · #10 ·
Thanks for posting. Very informative. I recently bought a Chevy Aveo 2011 LPG model in Thailand for office commute. For some reason, the car consumes some amount of petrol even if it runs on LPG mode. The LPG switch is always ON. However, the fuel indicator for petrol shows the amount of fuel getting lesser over weeks. Not sure what is the problem. The worst thing is that Chevrolet closed their production and services in Thailand last year. Has anyone else experienced similar problem with their Aveo LPG/CNG?
Thanks for the comment, I still run the Aveo in the article daily, and it covers about 2000 miles per month. I have in the past seen reviews of factory converted lpg cars where the "journalist" has complained that even in full gas mode, some petrol (gasoline) is still used, as though this is a fault. The explanation is actually very simple.

Firstly, all lpg cars that use lpg in vapour phase (gas) need to start and run on petrol up to normal operating temperature. This is because "boiling" the liquid gas such that it becomes a gas requires energy, which is obtained from the water cooling system in the pressure reducer. If you try to run on gas when the engine is not at full temperature, the reducer cannot provide enough gas for the engine to produce full power, and may even (literally) freeze up as well as running very badly. The UK is generally a little cooler than Thailand, and for the summer, I have the software set to 15c as the best switch over temperature, which results in only a matter of seconds running on petrol, in winter, it is set much higher. If you are out of petrol, on most systems, you can force start on lpg by holding the lpg button at start up, with the proviso that you allow it to tick over UNTIL FULL OPERATING TEMPERATURE IS OBTAINED, before placing the engine under load.

There is another time when lpg cars burn petrol, and it is due to the way the gas injectors work. Petrol injectors are fed from a high pressure fuel rail, when the injection pulse is sent to them, the electromagnet pushes the injector open, and the petrol enters the port (manifold) under pressure. When a gas injector opens, a tiny magnet, which normally sits closed, is lifted against the tension of a spring, and lets the low pressure gas into the port. Have a look at this repair kit:


Now, when an engine is on over run, (no throttle, in gear), the engine management switches off the fuel injection to save fuel. There is a crucial point however (normally just as you go from over run, to dipping the clutch), when the vacuum in the inlet manifold is very high, and it is so high that the lpg injector is held shut because the vacuum produces more force than the electromagnet can overcome to open the injector. At this point, the engine stalls. This is a well known condition, and the lpg ecu manufacturers apply a feature such that when this pressure differential is detected by the lpg system's vacuum sensor, it MOMENTARILY turns the petrol injectors back on for a few cycles until equilibrium is restored. This feature is turned on by a tick box in the software, and the effect can be seen if it is turned off. You will never see, or feel the system doing this, however, over time, and particularly if used on urban routes with a lot of slowing down, junctions, etc, petrol will be consumed.

For guidance, my car uses about 5 litres of petrol per 2000 miles, and over about 106,000 miles on gas, has been on gas 98% of the time, as recorded by the ecu. It is now used as an urban courier car, so lots of the conditions outlined above.

Hope the explanation is clear, if not, please ask.
 
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