LPG Conversions

[Bear Senior Member Find all posts View Profile Close Bear]

Sprint gas system just fitted. Up and down the Toowoomba range and around town I cannot detect any difference between gas and petrol. Early days yet though. I'll try to report some figures in a few weeks.

[Stevo Member Find all posts View Profile Close Stevo]

My figures are approx 5.5 k's per litre around town, to be honest, I don't hang around with the throttle. Have not done along trip yet so I hope the figures improve,
cheers Stevo

[Bear Senior Member Find all posts View Profile Close Bear]

G'day Stevo,
Do you know how those figures compare with petrol? I'll post mine in a few weeks. I guess at the end of the day ... or three or four years from now, its all just going to be academic. We will look back and count the money we have saved or wisdom we have gained.
Cheers
Bear

[Stevo Member Find all posts View Profile Close Stevo]

From all the info I have read in the forums, the petrol prados are doing around 6 to 7 k's per litre on average(around town).
My gas installer told me that there should only be a 10% diference between gas and petrol consumption.
But as I said I don't drive to save fuel, the biggest bonus to me having recently sold my turbo diesel, is the unlimited power on tap when you really need it.
cheers Stevo

[auza Lurker Find all posts View Profile Close auza]

Re: LPG Conversions

I've followed this thread for some time and was wondering if the consumption figures quoted included the gas and petrol portions? Most/all of these sequential vapour injection systems use both.

[auza Lurker Find all posts View Profile Close auza]

Re: LPG Conversions

I average sub 14l/100km on petrol only and 20l/100km on sequential vapour injection system (gas and petrol combined). Does anyone else think this is too high considering I rarely go over 2000rpm? My last trip was freeway only at 2000rpm and got 19l/100km. The log is here if anyone is interested.

www.c0de.com.au/temp/Prado_Gas_Consumption.xls

The vehicle is Prado 2004 V6.

[Bear Senior Member Find all posts View Profile Close Bear]

Re: LPG Conversions

auza, sounds a quite a bit high to me. Maybe the system needs a bit of a tweak. I have a recent Sprint gas conversion. Not sure what the figures are around town - but I don't think they are too flash. On a trip I just averaged 15.2l/100k. Petrol is 13.3l/100k. It's early days though, and although the system seemed to be running on gas for all except the first minet, I have no idea how much petrol has been used - the guage has barely moved since the instalation. Probably have more of an idea in a few weeks.

[auza Lurker Find all posts View Profile Close auza]

Re: LPG Conversions

Thanks for the feedback bear. The petrol gauge on mine doesn't move much either, but it'll use around 6-8l per 300km (town driving, less on freeway).

15- 16l total consumption is where I'd like to be. I'm taking it back for a second tuneup soon, so we'll see if it gets any better. The 1st tune up made it run smoother (had a very heavy vibration on gas and very noticeable dead-spots), but didn't do much for the consumption.

[Bear Senior Member Find all posts View Profile Close Bear]

Re: LPG Conversions

OK, just completed a fairly accurate test. Filled with gas and carefully topped up the petrol.

416.2ks = 66.58l gas + 1.82l petrol.

After allowing for the fact that it was 7.2ks from an empty gas tank to the fill up, by my calculations, gas consumption was around 16.5l/100. Also, less than one litre of petrol for the full tank of gas. Or,

409.0ks = 66.58l gas + 0.8l petrol - pleasantly surprised at the low petrol usage, especially as half was stop start and up and down the Toowoomba range.

To explain these figures a bit more. Almost exactly half was highway - with tyre pressure at 31psi as we were heading off road for a bit. The other half was a combination of up and down the Toowoomba range, around town and a small bit of off-road. On petrol and with the tyres at 38psi, I average around 15l/100k up and down the range and 13.3l/100 on the highway @ 105k. Allowing for a bit of increased consumption due to low tyre pressure, consumption increase on gas over petrol would be around 15%.

[jeremy Lurker Find all posts View Profile Close jeremy]

Re: LPG Conversions

Sorry, a bit off this specific topic BUT did we ever find a solution to the fuel gauge only going to half way for a full tank of petrol after an LPG conversion?

TKStrong was looking into it but haven't heard much in months.

Consumption 16L/100km gas
13.5L/100km ULP

[Bear Senior Member Find all posts View Profile Close Bear]

Re: LPG Conversions

Jeremy, does your fuel guage work ok from half? Or does it not work at all? Sorry I don't know of a solution - just curious and wondering if it could be a warranty matter. The fellow that installed ours mentioned that some prados have fuel gauge issues and he "hoped" they had a solution - of course he mentioned it AFTER we had paid :wink: . Ours seems to be working OK, but it does show the reserve light.

And auza, do you mind me asking what system do you have installed? Our installer replaced a set of injectors on ours a couple of days after installation - it was running rough - and he mentioned that a bad batch of injectors will result in poor economy. I don't know about the economy as we had only done a few ks before the fix.

[jeremy Lurker Find all posts View Profile Close jeremy]

Re: LPG Conversions

Bear, Goes to half when full and empty when empty, rather than full when full and empty when empty.

Was a big thread on this with the last entry in July so I suspect no answers.

[auza Lurker Find all posts View Profile Close auza]

Re: LPG Conversions

Thanks for all the info Bear. Your conversion figures seem pretty good. I would be happy with those.

Below worked out from my last data set (all freeway BTW)

Petrol only (based on 14l/100km): 324km
43.5l x $1.50 = $65.25

Petrol/Gas: 324km
8.8l x 1.50 + 57l x 0.7 = $53.10

Saving of $12 per week = $624 per year = 4 years to pay off conversion before any real cost saving occurs. If petrol were to go up, that may change to 3 yrs – still not worth it.

I'm off to conversion people now - we'll see if they can improve the system. If they can't it'll be time to start naming names.

BTW Jeremy - I also have the 1/2 full gauge issue. I would love to know if this has been resolved by anyone.

[Bear Senior Member Find all posts View Profile Close Bear]

Re: LPG Conversions

Jeremy wrote:

Goes to half when full and empty when empty, rather than full when full and empty when empty.
Was a big thread on this with the last entry in July so I suspect no answers.

Does sound that way a bit. I reckon I could live with that ok, just so long as it works well enough to know when it needs filling.

I do think auza has a real case though. From what i've read here and elswhere, an increase in consumption between 10 and 20% is reasonable. Auza, I would try to be friendly ... assume the installer will do the right thing, but expect him to as well. Sounds like there is definitely something wrong with your system.

Jeremy, do you find the same thing as me ... hardly any petrol used at all?

[auza Lurker Find all posts View Profile Close auza]

Re: LPG Conversions

Bear, I will try the friendly approach first of course ;-) Although my patience in starting to wear thin. I've had real trouble getting hold of anyone... the last time the only way I got hold of someone was to pretend to be a new customer (on website)... I got a call in an hour.

Tuneup done today... so we'll see how it goes, plus I'll make sure the tyre pressure remains constant (thanks for the tip).