Duel fuel or not?

[johnvtls1]

theres a reason why the car blows the air box cos its not working properly if u find the problem everything will work fine. maybe it needs a tune

 

[Ron41]

I was very hesitant at first before changing over to lpg, but now approx 12 months later i am so glad i had it changed, never ever backfires or any other problems so far, i told the gas fitter to put new good leeds in, new spark plugs and filter when he installed it.
The boot space the tank takes up has not worried me in the least either.
I do think that a good gas system & installer is paramount and keeping the car serviced properly is just as important.
[My choice] is to warm the motor up on petrol, then once warm i switch it to gas, i also switch back to petrol periodically for a few klm's whilst doing country driving, this only costs me about $20 of petrol per month doing it this way.
Everyone will have different views on this but i think its the best thing i have done to my car.

 

[Cheap6]

I no you hae to change the leads and spark plugs often how often.. are you ment to do this coz good leads can be $$$ same with sparkplugs.

it is somthing to consider now though.. they reckon fuel is going to go up again and there is talk about them taxing gas like the fuel but it still be cheaper...

I find the 'plugs last about 1/2 as many K's on LPG than they did on petrol (I change them when I get a slight stumble at idle, rather than on a km basis). GM recommends the plugs should be changed at about 1/2 the km interval they say for a car not running on LPG; 20Kkm vs 40Kkm. So, I change the 'plugs once (or so) per year instead of every 2 years = an extra $15 per year or $0.30 per week. Leads??, but they're only $50 or so any way and I have replaced one set in about 50K km on LPG.

An excise will be applied to LPG starting 2011 at 2.5cpl and increasing 2.5cpl per year up to 12.5cpl. GST is applied to the excise ie. multiply it by 1.1 and LPG has a lower energy content per litre than petrol, so multiply it again by 1.3 to get a petrol equivalent. Petrol has an excise of 38.15cpl applied, again with GST on top.


LPG excise @ 12.5cpl: 12.5X1.1X1.3 = 17.9cpl

Petrol excise: 38.15X1.1 = 42.0cpl

on the basis of equivalent energy content.

No one can know what the base cost of the fuel underneath the excise will be but LPG is extremely unlikely to exceed the cost of petrol.

 

[azkwazere]

Youll find that alot of issues related to gas can be minimised or eleminated by going with a straight gas setup, ie. No petrol. Injectors drying etc..

400 a month is actually quite reasonable, for a petrol car. v8's will take about 100 to fill and i know most will do a tank a week... so thers the 400 right there.

My personal opinion would be if you need to save some money on fuel then switch to gas, but, do it right and get it fully installed as a standalone gas system and get it done professionally. Then maintain it well. should serve you well.

aZK.

 

[Ben1988]

is there much differnce between getting it direct injected or having the mixer and the gas seperate.. i no with direct injection your not ment to loose much power.. and its better but its apperntly more expensive i want to keep my car on petrol as well keep it duel fuel i only want the gas for travelling to and from work and then when i go out im planning to run it on fuel i no the car will use more fuel coz its tuned for gas and then down the track i am planning to buy a weekend going out kinda car and keep the ute 100% for work
i guess its one of those u have ppl that like gass u have ppl that hate gas i was always one of those ppl that reckon gas is wat u use to run ur bbq not ya car but the cars getitng old its only for work if it saves me money then why not..
just have to weigh it up compared to the mantaice and issues u have with gas

 

[Cheap6]

Read the Gas converted VT thread for most of what needs to said re. injection (SVI - sequential vapour injection) vs mixer (carb.) systems. (I know there's a lot of posts in it ). Driving a car with a well set up mixer LPG system will convince you that SVI is unecessary if you can arrange to do so.

Apart from having to drag around 30 or so kg of petrol tank and fuel, there is no real difference between a car running dual fuel or dedicated gas. A twin map (factory LPG) Memcal will allow the ignition timing to be optimised for LPG (and there's not all that much difference vs petrol), which is about all you could justify economically anyway.

Were you to rebuild an engine specifically for use on LPG, you could make meaningful changes to better suit the fuel, but if you are not rebuilding the engine for another reason (and I know that you have just replaced the engine in your car), it is not an economical move to do so just to better suit gas.

It will be easier to set the LPG up if the car can start on petrol (most, but not all, do) and it becomes possible to use the factory Memcal in the computer to fire the petrol injectors to protect the exhaust valves when needed (again factory Memcal).

 

[Ben1988]

thanks for the info... im just waiting and seeing how much its going to cost me and work out what i want to do.. i want to see how the fuel economoy is with the new engine and everything in.. i had the radiator reco as well new thermostat gear box serviced and ihave a 69mm throttlebody and a cold air i used to average about 480ks from a tank its a 55ltr tank in the utes and just over 600 on the hwy so bee interesting to see if its any diff with the new engine

 

[deanom]

This has been an interesting thread. I have Factory Impco Gas on my VS and it has been great. The issue with fresh plugs is very true and it also hates leaks in the inlet system so a bit of tightening of clamps works wonders. Apart from that it smooth and economical with great response.

I have put a Morey's lube kit on and judging by plug colour I would suggest the distribution of the product might not be all that even. The injector nozzle was installed into the throttle body just beyond the butterly.

I would be interested if anyone has ideas on the value of upper cyl lube and also any ideas on the best way to mix it with the airflow. When I replaced the old donk there was some degree of valve seat recession though I did not have a lube kit on that engine.

 

[vr_executive]

I will never have it back on my car, I always maintained it and had it serviced every 10,000 klm and still had nothing but trouble,

 

[Clacker]

I will never have it back on my car, I always maintained it and had it serviced every 10,000 klm and still had nothing but trouble,

Is that maintaining and servicing the engine?

Have you had the gas setup looked at and adjusted?

What problems are you having?