Advice on VX LPG Conversion

[Spadge]

Im currently investigating getting a LPG conversion on my car (VX commodore V6 Auto)

Ive spoken to a couple of installers and they give me a few pros and cons but of course they want your business so i they will sugar coat anything

I want to know from any of you out there that have LPG on their VX what to look out for.

heres a few things im keen to find out more about

1. price on a conversion (cheap and not so cheap)
2. Fuel Efficiency. I currently get about 11-12 litres per 100km on petrol
3. Approx savings per week (or per tank)
4. Performance difference
5. wear and tear... does having gas kill motors/seals/gaskets/valves/valve seats

i travel about 20,000km per year mostly suburban travel although with having LPG i would be more likely to go for longer drives.

Is it worth getting it done or not... i know petrol is around 80-90c a litre dearer than LPG but theres more things to consider....

ive been told that conversions arent good for VX's as it causes problems with valve seats recessing, and backfiring which could cause head damage and a nice repair bill...(this was from the RAA) and then was told i would need to spend $3000-$3500 on a direct injection system as well and theres no way i want to spend that much either

any hints, tips or advice would be much appreciated

 

[deserthead]

1. price on a conversion (cheap and not so cheap)
2. Fuel Efficiency. I currently get about 11-12 litres per 100km on petrol
3. Approx savings per week (or per tank)
4. Performance difference
5. wear and tear... does having gas kill motors/seals/gaskets/valves/valve seats

Is it worth getting it done or not... i know petrol is around 80-90c a litre dearer than LPG but theres more things to consider....

ive been told that conversions arent good for VX's as it causes problems with valve seats recessing, and backfiring which could cause head damage and a nice repair bill...(this was from the RAA) and then was told i would need to spend $3000-$3500 on a direct injection system as well and theres no way i want to spend that much either

any hints, tips or advice would be much appreciated

Well I might aswell go first.

I got mine converted bout 3 months ago. And I haven't looked back since.
I did, what ur doing now, research which is wot u need to do for something like this.

To answer your questions:

1 - I rung around to get prices, this was September last year, took 6 months for the tank to come. I went with the place that sounded like they knew what they were talking about on the phone, turns out they do, luckily!!
Cost me $3050. Ur not guna get out of it cheap. Those direct injection systems r worth more than that. This is the average price these days. Included in the price was the Flashlube kit, which combats the valve recession.

2 - I'm getting roughly 450 odd ks to a tank. Which is not bad for 60 useable litres. Long distance, I seem to get the same.

3 - This is my favourite part!! :dance: When I fill up 55L, I did this last night. Gas was 49.7c/L petty was $1.439/L. I saved $51 bucks difference between the 2. Average is bout 50 bucks a tank saving. SO in the 3 months i've had it, I've saved bout 580 bucks already. . . . .

4 - Power wise, to my surprise, no difference. I thought it was going to be noticable but its negligable. Which is tops!!!!

5 - Gas is better for your engine than petrol is!!! Its a dry fuel, meaning when u start it in the morning, the gas isn't going to wash the oil away, like petrol does, meaning a better lubed up engine when its cold. Doesn't poulte the oil as much either. Downside is u need to service the system every 20k, which also means plugs every 20k. But hey on the savings who cares!!! Basically ur engine will last a shite load longer on gas than it will on petrol.

So basically YES, YES it is worth getting it!!!!!!!
To combat the valve recession as I mentioned, get a flashlube kit installed. This is the upper cyclinder lubricant.

I had people say the V6 is poo on gas, but I've had no troubles at all!
Best decision I've made on this car to date!!

Hope this helps ya out mate.

Any other questions, just ask.

 

[Shounak]

Exactly what he said.

Backfiring only occurs when the gas system isn't well tuned. It needs an annual tune up by a specialised LPG place. It costs about $165 and you can't not do it..

It's good when you change your oil. When you change your oil after 10k the oil still has a nice honey colour to it..

You also have to run it on petrol a bit.. I run about half a tank every month.

Any other specific questions, just shoot. We've both got converted VX's and both of our cars run beautifully..

 

[minux]

My opinion is this, for 20,000 km's a year it isnt worth doing, it will mean you will have to have the car for 4 + years for the conversion to be worthwhile.

Im basing that on costs vs kilometres...thats what it come up with provided fuel doesnt exceed $1.80 litre and goes doesn't exceed $0.90

 

[yeah.yeah]

I agree with the above the vx is fine on gas. The only thing is I got the proper vx factory fitted gas system with a 75litre tank for $2540. I dont know if there a price difference between states or not but I'm in SA.

 

[emmtee83]

i've got a factory lpg tank on my 2000 VT, and power-wise, between petrol and gas, i can't notice a difference on gas. gas tanks over here in SA are roughly 1500-2000 and if you're paying 1.45 cpl for petrol and 51 cpl for gas, the saving is instant. for me, it's at least 35 per week, 35 x 52 weeks = 1820 (the rough cost of the conversion). one year, you've made your money. i've found i can get up to 700 kms on country travel, about 420 on city driving.

Plus everything deserthead said. I specifically looked for a Commie on gas, so that i could cash in on these benefits. Good luck.

 

[WAGON MAN]

Well I might aswell go first.

2 - I'm getting roughly 450 odd ks to a tank. Which is not bad for 60 useable litres. Long distance, I seem to get the same.

5 - Downside is u need to service the system every 20k, which also means plugs every 20k. But hey on the savings who cares!!!

get a flashlube kit installed. This is the upper cyclinder lubricant.

I had people say the V6 is poo on gas, but I've had no troubles at all!
Best decision I've made on this car to date!!

Hope this helps ya out mate.

Any other questions, just ask.

I have had my wagon on gas for 2 1/2 years and done 45000kms.

I get 400kms per 55 (useable) litres city and about 470kms on the highway.

I used to have a Mitsubishi express on gas and used to get that tuned every 20k (no computer ) BUT i have found on the VX that i haven't had to have the gas system serviced yet.I have changed the plugs at the 80k service and its still running the same as the day it was converted.The computer keeps it well tuned!!!

It will be one of the best decisions you will make....

Your wallet will thankyou for it ( in the long run) and you can quitely chuckle to yourself at the servo when you see the person next to you putting in
$50 - $120 of unleaded.

Check these out....

http://www.lpgaustralia.com.au/index.cfm

http://www.lpgautogas.com.au/index.cfm?Action=Convert


Deserthead i'd like to ask a few question

Are you running a standard air filter element?

Long distance klms is Vx loaded up (weight)?

Could you enlighten us about your flashlube system,i have read a few of your posts + seen your photos, are you still going to relocate it?

The kits worth about $80 is it easy to install?

Where did you get your conversion / servicing done at?

 

[deserthead]

Deserthead i'd like to ask a few question

Are you running a standard air filter element?

Long distance klms is Vx loaded up (weight)?

Could you enlighten us about your flashlube system,i have read a few of your posts + seen your photos, are you still going to relocate it?

The kits worth about $80 is it easy to install?

Where did you get your conversion / servicing done at?

Yep, just the standard air filter.
I thought of maybe a K&N, only for the reuse thing, but meh, I can spend 100 bucks elsewhere.

Long Dist, the car only had my bag in it which had clothes, was for a weekend. So not really out of the norm. Heading up to Brissy second week of July. Will c how it goes again.
Although, on petrol I almost get 1000ks out of a tank. Which is freakin awesome!!! :dance:

The Flashlube, I just got em to chuck it on with the install. Peace of mind. They said the heads could handle the gas, but I didn't want to find out the hard way they couldn't.

Yeh, I am going to move where the hose goes into the plenum. I was reading somewhere, wish I could remember where! But this dude had a LPG VT 6. He had to have his head replaced after like 40000ks or something like that. He had flashlube too. The mech said to him, the rear valve seats were fine, it was just the front ones that were shagged. It was cause they put the flashlube coming into the back of the plenum. On the instructions it says, put it in the throttle body. So ever since reading that, its been in the back of my mind to move it.

Um place I got it done at was AAA at Castle Hill Sydney. Was the only bloke that sounded like he knew what he was on about with the commies.
Turns out, there were dramas, cause Holden never made the LPG system to suit manuals, only autos. But they got around that, luckily.

Sorry for the longish post. . . . .

Minux, I agree with u there. U either need to keep the car for a while to make it worth while, my case will b 6 odd years or so. I'm not into replacing cars every few year, to keep up with the jones. Better things to spend my money on. Either that, or u need to do the ks.

 

[Spadge]

thanks for the info guys its all much appreciated

i thought it was a little strange that someone would just come out and say that LPG on a VX would cause problems. The guy said it was pretty much the same with all aluminium heads

im definitely keen on doing it though.. i worked it out and it will take me just over a years savings to pay off the system

im also not one to change cars regularly.. i had my last car for almost 9 years
i love my VX and im definitely looking at keeping it long term

with the flashlube... how much on top of the conversion did it cost to have installed?
its something i will ask about when i talk to people about it

 

[WAGON MAN]

Thanks Deserthead.....:wave:

The info about the flashlube is interesting.
Let us know how you go with the relocation.
I'm considering a Flashlube system. Its a small investment for Peace of mind..

http://www.flashlube.com.au/store/products.pl

I highly recommend a gas specialist called the Gas Man at Alexandria.