Hi all,

I could not find thread with this question so I'm posting one. I have '05 es magna sedan, auto. I am wondering if it possible to do lpg conversion on this model. How much it would cost and any downsides?

Yes it's possible on just about any car (not sure about diesel engines but thats a different matter)
You'll need to contact someone who fits LPG systems.
Downsides are loss of power (especially if not tunes right) and loss of boot space.
Can sometimes lead to more engine problems and shorten the life of the engine if done incorrectly
If done incorrectly, car may also explode so make sure you get it done professionally!

Yes it's possible on just about any car (not sure about diesel engines but thats a different matter)
You'll need to contact someone who fits LPG systems.
Downsides are loss of power (especially if not tunes right) and loss of boot space.
Can sometimes lead to more engine problems and shorten the life of the engine if done incorrectly
If done incorrectly, car may also explode so make sure you get it done professionally!

Also an increase in fuel consumption of between 30-40% approximately when running on gas, which is obviously offset by the lower price of LPG at the pump

I have a LPG mixer system installed. Car uses 12.5L/100km on petrol or 14.7L/100km on LPG along the same route, traffic conditions. I have had it as low as mid 13's . These figures are CITY numbers. On the highway LPG drops to around 11L/100km

As for power, i dont notice it. The dyno confirms this. On a dyno, petrol has 2kw more based on my car and tune etc. Part of this comes from the size of the convertor fitted.

So i take both those things into consideration, i can handle the smaller boot space. The way I look at it, its basically 50% cheaper for me on LPG. I sure know 70cpl is much nicer than the current $1.60 for regular unleaded.


I cannot comment on installation cost as mine was fitted by a qualified installer who is also a friend. Its also illegal to be installed by someone not licensed.

There are 2 types regularly fitted to these.
Mixer type, which is small gas ring inserted before the throttle body, regulated by manifold vaccuum.
And,
Sequentially Injected Vapour systems. SVI for short. At about $4000, these are double the cost of the mixer type. Check with your state for government rebates, Mine was $2000 at the time, which meant a mixer could have been had for Free! that was 5 years ago though...
These are computer Managed, Individually (6) Timed and firing order sequenced Injectors releasing Gas vapour into the lower part of the upper intake Manifold...
Usually the most economic and powerful of the two.... A good installation is worth its weight in gold.

Kits vary in price and quality, just like anything else, Best Kits - Impco for the mixer type, and its arguably BRC for the SVI..
I have the latter and now getting 13's with the Manual.... While the petrol is more powerful, I have no issues with the LPG.... :D
The standard Tank (for the magna) is 82 litres and at an 80% fill limit, equals about a 65 litre fill.
So 400km city to 700 km Hwy are quite acheivable on a Tank. Depending on how well the system is setup and tuned.
So its not too bad, and stops at the gas station are not as frequent as some would imagine.

Boot space is comprimised, but my magna with a spare, a sub, amps and a Tank. Still has more space the the old mans commode with just a tank and a spare, I can still carry a large esky, or 2 suitcases. The 380 boot is quite small after the Tank is fitted.

If you have a crap system you'll hate it. Til it gets sorted, and every man tells you he can fix it, but few gas techs are actually any good.
If you have a good system, you'll never look back.... I think I've done about a 100k in mine now, and replaced a $12.00 filter... Thats not bad.

The commodore of fathers is rated one of the best systems, he loves it, but refuses to run if its not serviced every 10,00km.. I laughed...

If you are having LPG installed, it can only be injected LPG. The mixer type is illegal to install on cars that are later than 2004.

If you are having LPG installed, it can only be injected LPG. The mixer type is illegal to install on cars that are later than 2004.
Cheers Tee Jay 2, Thats good to know..
Could be rather expensive venture...

Absolutely does make it expensive. Mixer type is about $2000 and Injected type is closer to $3500. Both of these are before the rebate from the government. It is still $1500 difference regardless of the rebate.

Hi all,

I could not find thread with this question so I'm posting one. I have '05 es magna sedan, auto. I am wondering if it possible to do lpg conversion on this model. How much it would cost and any downsides?

As mentioned above, almost all cars can get lpg installed. Some just require more work that others.

The magna runs fine with both injected or mixer style systems. I've heard good reports with both systems.
Personally I have a closed loop MIXER system installed and it's been quite reliable system. Starts on petrol and switches to lpg after a start so I've never had any backfire or other issues starting. I've replaced my spark plug and leads more suited to lpg and it's been great. Being a mixer system I've lost a bit of power and it does use more than it would on petrol, but the cost savings ($0.70/litre vs. $1.50/litre for petrol) easily outways the disadvantages. I use around 18L/100km on lpg with harder driving in the city and I only lost 8kw of power (dyno verified). Also the lack of boot space isn't a too big concern with me because I've got a towbar and roof racks.

It cost me $1500 to install using a 2nd hand tank that was rechecked and guaranteed for 10 years. The rebate at the time was $1500 so it was effectively free. Now the rebate is $1000 and the quantity of rebates is capped per financial year. The rebate will cease in 2014.