LPG fuel economy V6 Auto

[chesty Lurker Find all posts View Profile Close chesty]

I have a V6 Auto 4 speed with a Tartarini LPG Sequential Gas Injection system and am consistently getting around 340km's per 67 litres of LPG. I mainly do shorter city driving as I haven't been able to get out on any longer trips yet. Considering the Tartarini SGI system starts on petrol and switches to LPG when the car is warm I am thinking this economy is pretty poor. By my math I am getting around 19.7 litres per 100km but when you factor in the petrol start it will be over 20 litres.
Can anyone with a V6, auto or manual, on LPG please share their mileage figures. I know this system measures the 02 sensors and adjusts the gas injection accordingly but there are also some base line figures that I may need the LPG installer to have a look at if others are getting better economy.

Cheers
Chesty

[pointnepean Lurker Find all posts View Profile Close pointnepean]

Re: LPG fuel economy V6 Auto

Hi Chesty, I have a 2004 GXl on Gas and am getting around 400 to 440 during medium driving out of 64 litres. The only difference is mine is a manual.

The only thing I can think of with your fuel economy is tyre pressures or roof racks can have a detremental effect.

Cheers

[watsoga Lurker Find all posts View Profile Close watsoga]

Re: LPG fuel economy V6 Auto

Hi Chesty
I have a 2004 VXV6 Auto
Can you give me some info on your gas conversion, as I am looking at converting mine

thanks

[chesty Lurker Find all posts View Profile Close chesty]

Re: LPG fuel economy V6 Auto

Its a Tartarini Sequential Gas injection system. I had it fitted about 2 years ago and it has been very reliable. Being vapour injected there is no stumble when switching between petrol and lpg. I had it fitted by Frankston Gas Conversions and it cost $3750 from memory. The install is neat and tidy and it is a quality system.
Let me know if you need to know more.

[lc120_man Advanced Member Find all posts View Profile Close lc120_man]

Re: LPG fuel economy V6 Auto

Got the same LPG system in mine - with standard size tyres and no roof rack (but with 2" lift and other mods) I get about 380-400km from 70liters....
Bigger tyres and enonomy goes down to about 320-350 km
and a camper and roof rack on freeway - economy goes down to 250 km
The worst fuel economy so far was going down from Alice Springs at 130km/hour - 200 km from 70 liters ...

Stan

[pointnepean Lurker Find all posts View Profile Close pointnepean]

Re: LPG fuel economy V6 Auto

Hi LC120, Have you had any problems with the petrol fuel guage? If so have you found a fix?

[boof Member Find all posts View Profile Close boof]

Re: LPG fuel economy V6 Auto

Hey guys I am looking into putting ours on Gas at present would you say its worth it? The economy seems pretty poor from the figures above, also with the extra tank where does it go, do you lose the second 90L petrol tank to install it?

[lc120_man Advanced Member Find all posts View Profile Close lc120_man]

Re: LPG fuel economy V6 Auto

Hi LC120, Have you had any problems with the petrol fuel guage? If so have you found a fix?

Pointnepean,

There is only one issue I found with the fuel gauge, which you would only notice if you do a lot of km in a day:
when running on LPG - the petrol fuel gauge slowly going down as if it is using petrol... This is is mainy evident
on very long day drives. If you turn the car off (sometimes for couple of minutes, sometimes for couple of hours) the petrol
fuel gauge would come back to proper setting...

[lc120_man Advanced Member Find all posts View Profile Close lc120_man]

Re: LPG fuel economy V6 Auto

Hey guys I am looking into putting ours on Gas at present would you say its worth it? The economy seems pretty poor from the figures above, also with the extra tank where does it go, do you lose the second 90L petrol tank to install it?

Just do your numbers, depending on how many K's you do a year... Mine car does 30K+ a year and cost appox $30 per week on LPG in fuel costs..
The rear 90 liters fuel tank gets removed and you can put another 70-80 liters (usable) LPG fuel tank in it's place.

[boof Member Find all posts View Profile Close boof]

Re: LPG fuel economy V6 Auto

Hey guys I am looking into putting ours on Gas at present would you say its worth it? The economy seems pretty poor from the figures above, also with the extra tank where does it go, do you lose the second 90L petrol tank to install it?

Just do your numbers, depending on how many K's you do a year... Mine car does 30K+ a year and cost appox $30 per week on LPG in fuel costs..
The rear 90 liters fuel tank gets removed and you can put another 70-80 liters (usable) LPG fuel tank in it's place.

Cheers mate is that a majority of around town or highway driving? We are doing a similiar number of ks a year so it may well be worth it.

[pointnepean Lurker Find all posts View Profile Close pointnepean]

Re: LPG fuel economy V6 Auto

Hi LC120, Have you had any problems with the petrol fuel guage? If so have you found a fix?

Pointnepean,

There is only one issue I found with the fuel gauge, which you would only notice if you do a lot of km in a day:
when running on LPG - the petrol fuel gauge slowly going down as if it is using petrol... This is is mainy evident
on very long day drives. If you turn the car off (sometimes for couple of minutes, sometimes for couple of hours) the petrol
fuel gauge would come back to proper setting...

Thanks LC120,

I have the guage only ever coming back to half from empty and the 90l light not working, have you had any experience with this?
Cheers PN :?:

[boof Member Find all posts View Profile Close boof]

Re: LPG fuel economy V6 Auto

Have booked ours in next week for the install so will be interested to see how it goes 8)

[WA_Prado Lurker Find all posts View Profile Close WA_Prado]

Re: LPG fuel economy V6 Auto

I have just completed a 2100km fuel test using only LPG as the main fuel source in a 2003 GX 4l V6 Manual.

In total I used 444l LPG and 34l Petrol.

Or --- 21.1l LPG / 100km and 1.62l Petrol / 100km.

In total it cost me $12.36/100km. But that will vary on how much you pay.

Driving was a range including a couple of 4WD runs. Some freeway work, and toodling around the city.

For each fill the LPG varied from 18.6l to 26.0l / 100km.


Cheers,

[WA_Prado Lurker Find all posts View Profile Close WA_Prado]

Re: LPG fuel economy V6 Auto

I have the guage only ever coming back to half from empty and the 90l light not working, have you had any experience with this?
Cheers PN :?:[/quote]


Initially my fuel gauge went from full to emplty with the 90l light on. After a while the 90l light went out and the gauge only goes from empty to half.

Last time it was in for a servie the guy said that they put in a 5 ohm resister to trick the system into thinking the old tank is still there and that my resister had blown. He didn't have a replacement and i have gone past worrying about it.

I have read in places that by varying the resistance of this resister you can get the fuel gauge to read from empty to half or full etc.


Cheers

[anthill Lurker Find all posts View Profile Close anthill]

Re: LPG fuel economy V6 Auto

This is exactly what ours does. We had the tartarini system installed almost two years ago. The petrol fuel gauge only goes between empty and half full. No red light has ever come on. I am not sure if they have done the resistor thing.
Also noticed that it takes a while to move from half to a quarter, but from there it drops a lot quicker.

As for fuel economy, my wife drives ours mainly locally. ie to shops and things. On the weekends I might take it a bit further. But we generally get aroun 380-420 out of a 68L (useable) tank. Which for us is just over a week. Also because the system starts on petrol and because we do a lot of short trips, we go through a bit of petrol as well, maybe 10L a week.

Overall not sure if its good or bad, but it fits nicely into us getting it filled at the same time every week.