VN Calais L3 Trip and Gas

[88GreenVN]

Now that I have a VN Calais on Gas I can say what happens with the fuel readings.

If you keep using the gas the DTE goes up as your travelling more K's and not using any petrol. So resetting the trip computer each fill is a good idea.

Both petrol and gas are reported on the middle screen and dont change when you switch between the 2. So if it is using AVG. 11.5 L/100 kms on petrol and you flick it over to gas it stays on 11.5 AVG.

The low fuel light goes off when getting low on petrol (10 Litres left).

[rob drag racer]

i had the same problem with a nc fairlane on gas it was truly a pain in the ass lol

[88GreenVN]

i had the same problem with a nc fairlane on gas it was truly a pain in the ass lol

Yep - reset every fill would be the only option I'd say.

Not sure how I'm going to work out economy figs yet - I guess I'll just use one fuel for a few tanks the change over to the other.

[rob drag racer]

Yep - reset every fill would be the only option I'd say.

Not sure how I'm going to work out economy figs yet - I guess I'll just use one fuel for a few tanks the change over to the other.

thats about the only way to work it out the only thing that's relay an issue is the economy with gas is so much different to petrol making an average harder to work out i gave up in the end

[levymetal]

hey shane, i don't know if you can ever get the avg fuel correct on gas. i tried calibrating it on my car but was always off by many litres per tank every time i tried to put in new figures. i think a big problem is that your calculations are based on how much gas you can get in the tank, yet this differs a lot with temperature.
never even looked at DTE

[delcowizzid]

the litres per km and everything else displayed are worked outr on injector pulsewidths so by rights on LPG it isnt going to give you any usable figures due to the injectors not feeding in any fuel the ecu is only handling the timing dside of things on gas

[88GreenVN]

the litres per km and everything else displayed are worked outr on injector pulsewidths so by rights on LPG it isnt going to give you any usable figures due to the injectors not feeding in any fuel the ecu is only handling the timing dside of things on gas

So as the kms clock up the car trip computer thinks no petrol is used so DTE starts to look better and better.

The instant still works while on gas - umm well I thing it did. How would it work this out is no petrol is being used?

I'll have to have another test drive tonight.

[levymetal]

i think it's because the car doesn't know it's on gas and it's still sending those injector pulses, but the injectors are grounded out when you're on gas? so it still shows up on the dash how much you would have used if you were on petrol. i can't remember exactly how it works though.

[88GreenVN]

i think it's because the car doesn't know it's on gas and it's still sending those injector pulses, but the injectors are grounded out when you're on gas? so it still shows up on the dash how much you would have used if you were on petrol. i can't remember exactly how it works though.

Well that sounds about right to me. Thanks

[delcowizzid]

if its running a gas tune it cuts all injector pulses

[88GreenVN]

if its running a gas tune it cuts all injector pulses

So the instant would not be displayed? or just stay at the last reading?

[delcowizzid]

hard to say it may stay at the last reading but ide think it would zero out

[88GreenVN]

hard to say it may stay at the last reading but ide think it would zero out

Will test this tonight - take the car for a run see what both fuels read instant and avg.

[levymetal]

my instant and avg works (just not accurate). i actually remember asking my gas installer what would happen and they said they'd do it like i said above so it would still show the readings. so it looks like my car doesn't cut the injector pulses altogether. btw i don't run a gas tune, it's still just the normal tune. i don't really know what happens when i hit that gas switch. my dads magna shows nothing when you're on gas.

i keep on editing this post
so basically what i'm saying is that when i'm on petrol, the readings are pretty accurate. when i'm on gas, it shows how much petrol i would have used if i stayed on petrol. but in reality you use more gas than petrol.

[88GreenVN]

Failed at test tonight - fixed the heater instead and now the VZ is parked behind it.

I gave up and sat down to a coffee - plan to do the test tomorrow now.