LPG fuel consumption

[dieseldude]

Hi, 1st post here. I just bought a 94 VR V6 with LPG conversion.
I did a search but could not find much info on LPG .
So far its using about 18/100 on gas,I have only used one tank and havent checked the petrol consumption yet.
I was expecting a little better
Previous owner says it was all serviced recntly although he didnt say exactly what was serviced.
Anyone have a LPG consumption figure?

[delcowizzid]

youll allways use more litres of lpg per 100 km than petrol thats lpg for ya might be cheap to buy but you burn more

[mrhotdog]

mine uses around that ive found sometimes more sometimes less, ive given up figuring it out for now lol, may just pay to get an LPG service (mixtures checked etc)

[buzuki]

you should use roughly between 10-20% more on gas then petrol, 18L sounds a bit high for v6. Id be looking at 13L for city driving.

Also next tank try to run it as low as possible, as gas guages arent really dead accurate. Most people when they hit the red have say ~ 60klm to go

even at that consumption its still cheaper to drive on gas

[commsirac]

Hi, 1st post here. I just bought a 94 VR V6 with LPG conversion.
I did a search but could not find much info on LPG .
So far its using about 18/100 on gas,I have only used one tank and havent checked the petrol consumption yet.
I was expecting a little better
Previous owner says it was all serviced recntly although he didnt say exactly what was serviced.
Anyone have a LPG consumption figure?

18L/100km is on the high side, but it depends on the type of driving. My vx gets only 16-17L/100km in heavy stop start traffic, but averages 14L/100km in regular suburban commuting. Highway is at ~10L/100km.

It would be helpful if you knew your petrol consumption, expect lpg consumption to be 30% higher. If its more 10% higher or lower than this then one or both fuel sytems is not performing properly and worthy of attention

[Deutscher]

Hi, 1st post here. I just bought a 94 VR V6 with LPG conversion.
I did a search but could not find much info on LPG .
So far its using about 18/100 on gas,I have only used one tank and havent checked the petrol consumption yet.
I was expecting a little better
Previous owner says it was all serviced recntly although he didnt say exactly what was serviced.
Anyone have a LPG consumption figure?

Well firstly matey, you can search all you want but never find anything great about LPG. But I have a 97 VS S2 Calais running on dual fuel. As calais I have a trip computer and my average on driving city/freeway is 9.9L/100KM. When I drive on freeway put cruise control on, sitting at 100 I get about 5L/100kms on gas (sometimes like 4.5 but I think that's when I'm just rolling ). Unless my trip computer is totally screwed and just gives random figures (when I accelerate my L/100kms increases and etc like normal, so I don't think it's faulty) which I doubt. I get better km's on gas than on petrol. I got my gas conversion done last year with the full rebates and it's running fine. On petrol I got like 300km's out of a fricken tank! with gas I get 500-550km's (70L tank). I'll admit I do drive a bit like a granny and stick to the speedlimit, I just use cruise control as much as possible.

Edit: I forgot to mention.... I have a CAI and K&N airfilter ... apart from that it's stock. I do have a full sound system, LPG tank in boot and the rest of the boot is a box with my sub... which weighs ALOT!

[djmenow]

I use my V8 5L VR everyday for a total weekly Km average of about 275km and it costs me at .43c per litre approx $25 per week in LPG. Plus I am a lead foot so I would be using less if I wasnt pushing it all the time.

[vr-man]

have you changed your plug leads for at least 8mm ones, i use bosch racing leads on my vr and have found them very good. also your plugs need to be regapped down to about 1.2mm stock gap is no good something to do with the gas ignition ???

[dieseldude]

you should use roughly between 10-20% more on gas then petrol, 18L sounds a bit high for v6. Id be looking at 13L for city driving.

Also next tank try to run it as low as possible, as gas guages arent really dead accurate. Most people when they hit the red have say ~ 60klm to go

even at that consumption its still cheaper to drive on gas

You dont have to run it near empty to get a fuel consumption figure,merely top it up and divide the litre by klms.

Yes, I will have to drive a little more and do a test on petrol
At least its confirmed I am on the high side.
Thanks for the help everyone

[illlusion]

the level 3 cluster can not calculate lpg usage correctly mine says the same but i have a 50lt gas tank with 46lt usable i get 300 to 330km to a tank and the trip computer will say i have used 22lt when i let my tank run out i get 100km on the red light too

[commsirac]

But I have a 97 VS S2 Calais running on dual fuel. As calais I have a trip computer and my average on driving city/freeway is 9.9L/100KM. When I drive on freeway put cruise control on, sitting at 100 I get about 5L/100kms on gas (sometimes like 4.5 but I think that's when I'm just rolling ). Unless my trip computer is totally screwed and just gives random figures (when I accelerate my L/100kms increases and etc like normal, so I don't think it's faulty) which I doubt.!

Something isnt right here!
If you can get those sort of figures running lpg, even leaned to the maximum the car will run at, then there should be a long line of manufacturers wanting to see what makes your beast tick!

Have you actually done calculations based on the actual amount of fuel used(what the pump says)/100km? or are just quoting the numbers off the instantaneous fuel consumption? what about average consumption?

[Deutscher]

Something isnt right here!
If you can get those sort of figures running lpg, even leaned to the maximum the car will run at, then there should be a long line of manufacturers wanting to see what makes your beast tick!

Have you actually done calculations based on the actual amount of fuel used(what the pump says)/100km? or are just quoting the numbers off the instantaneous fuel consumption? what about average consumption?

Well I am telling you what my trip comp tells me. But I have done the calculation and my average. Well my tank is a 70L, and I get 550 out of a tank (say 500 for bad week).
Tell me how to work it out please. (but how can my trip comp lie? when I accelerate off the lights it shows like 21+L/100km ... which sounds right, doesn't it.

[mrhotdog]

Well I am telling you what my trip comp tells me. But I have done the calculation and my average. Well my tank is a 70L, and I get 550 out of a tank (say 500 for bad week).
Tell me how to work it out please. (but how can my trip comp lie? when I accelerate off the lights it shows like 21+L/100km ... which sounds right, doesn't it.

550 wow, tell me how lol. ive got a 72 usable (havent got more than 68ish in before) and if i get 350 its party time lol, ive been told my CTS is stuffed but how do u get those figures

[buzuki]

i get up to 400 off 52 litres city driving, 600+ highway

[Deutscher]

550 wow, tell me how lol. ive got a 72 usable (havent got more than 68ish in before) and if i get 350 its party time lol, ive been told my CTS is stuffed but how do u get those figures

Uhh .... don't floor it, or do burnouts etc (like mentioned I granny drive my car ). I dunno lol.
550 is just after my red light comes on ... usually fill her up then. Usually as soon as I see the red light come on I'll go fill. Umm ... yer I can't tell ya anything bout my gas conversion ... cause I wouldn't have a clue... my car is stock xcept my CAI and K&N air filter. And I use cruise control if I have to go further than 20 meters in a straight line

Edit: Next time I fill her up.. I'll tell ya how many Litres etc I put in and how many K's exacly. (Seems like no one believes)

[Troy5L]

who cares is ya using that much gas, its that cheap just fill the tank up again for $30

[padrickz88]

who cares is ya using that much gas, its that cheap just fill the tank up again for $30

exactly finally someone gets it you would have to get between 20-30L/100 for gas to not be worth it....

do a service, and check your o2 sensor.... also your coolant temp sensor

i used to get anywhere from 12-16/100 in my old vn and that was mixed between suburban, highway, granny and thrash.... but when my knock sensor died the minimum i could get was 18, and that was mainly highway

[commsirac]

Well I am telling you what my trip comp tells me. But I have done the calculation and my average. Well my tank is a 70L, and I get 550 out of a tank (say 500 for bad week).
Tell me how to work it out please. (but how can my trip comp lie? when I accelerate off the lights it shows like 21+L/100km ... which sounds right, doesn't it.

How to calculate: 70/5.5 hundred = 12.7L/100km(a long way from your instantaneous readouts)
This figure of 12.7, is still perhaps quite good if it is an average of city and freeway driving, outstanding if it is just suburban commuting, or below par if it is freeway driving.
How can your trip computer lie, is it a factory system?. If not it is unlikely to be calibrated properly and possible is just using the airflow measurement that is for petrol consumption figures.

[Cheap6]

I have kept fuel consumption records since I converted my car, over a variety of different LPG tune configurations.

From that I have seen a high of around 22l/100km, urban to a low of mid 14'sl/100km urban. Highway is typically 10-11l/100km (but my latest tune looks really good on highway at est. ~7l/100km - I haven't done a full tank yet - with more to come).

I usually fill up from the same pump/servo at the same time of day and drive the same route each day but have noticed a big variation in fuel consumption figures over time. I can only put this down to changes in the LPG composition.

From this, I would suggest that measurement of consumption over several tanks is needed for an accurate consumption figure.

And, yes, while the fuel consumption figure from the trip computer will be reasonably accurate on petrol (based on injector duty cycle), on LPG it's a calculation and may bear little resemblance to what is actually going through the mixer, even on a factory system where the trip meter readout is calibrated for LPG.

[pjdm1980]

Just had lpg injection put on my V6 Supercharged '99 Statesman (160,000 KLM'S on the clock) and i get 450-500 KLM'S to 70 LTR'S (City and Highway) and it's got more power on gas than petrol and just as smooth, it's all automatic you can't even tell when it changes over. Cost me $1400 out of pocket ($2000 gov rebate) but i do 50,000 KLM'S a year, so i'm happy with it over all!!!!!!

[mrhotdog]

Just had lpg injection put on my V6 Supercharged '99 Statesman (160,000 KLM'S on the clock) and i get 450-500 KLM'S to 70 LTR'S (City and Highway) and it's got more power on gas than petrol and just as smooth, it's all automatic you can't even tell when it changes over. Cost me $1400 out of pocket ($2000 gov rebate) but i do 50,000 KLM'S a year, so i'm happy with it over all!!!!!!

not blaming my system but having an injected setup would help, ive got the basic mixer system. would it be hard and/or cost a lot to upgrade from what i have now to an injected system?

[Deutscher]

How to calculate: 70/5.5 hundred = 12.7L/100km(a long way from your instantaneous readouts)
This figure of 12.7, is still perhaps quite good if it is an average of city and freeway driving, outstanding if it is just suburban commuting, or below par if it is freeway driving.
How can your trip computer lie, is it a factory system?. If not it is unlikely to be calibrated properly and possible is just using the airflow measurement that is for petrol consumption figures.

Well my trip comp can't be that out then. My comp (factory) says 9.9L/100km on average. It's taken a lot of granny driving to get it down to that 9.9L is average btw.

[commsirac]

Well my trip comp can't be that out then. My comp (factory) says 9.9L/100km on average. It's taken a lot of granny driving to get it down to that 9.9L is average btw.

Your computer may be factory, but is your lpg system "factory"? If you trip computer says 9.9L/100km average and your actual consumption is 12.7L/100km, then depending on your appreciation of numbers, it is significantly out. In my vx with fact mixer system, the trip computer reading versus consumption measured by fill volume and km travelled varies by only +/_ 3%, which possibly is only due to the variation in when the afl clicks on.
Unlike cheap 6 , my consumption figures never show any signficant variaton, however, I cant claim that the lpg mix actually never changes as I have nothing to base that on.

not blaming my system but having an injected setup would help, ive got the basic mixer system. would it be hard and/or cost a lot to upgrade from what i have now to an injected system?

Its unlikely to be economically viable in the long term to convert to svi or lgi. Svi would be cheaper to do because at least the tank is kept the same. lgi needs a different tank as well.

[mrhotdog]

Its unlikely to be economically viable in the long term to convert to svi or lgi. Svi would be cheaper to do because at least the tank is kept the same. lgi needs a different tank as well.

i rang my local to find out a price, he reckons 3-4k to convert, i think ill keep the money

[pjdm1980]

i rang my local to find out a price, he reckons 3-4k to convert, i think ill keep the money

I wouldn't change if you already have a lpg system in but if your just getting a system in your car and plan on kepping it for a few years or do heaps of KLM'S then i say gas injection is the way to go, no doubts!!!