Dual fuels tanks how exactly does this work (pleas don't flame)

[fierce Lurker Find all posts View Profile Close fierce]

Okay before anyone flames me I have used the search function and the answers I fiNd relate to early models not mine, or come up with PDF and links that are now dead.

Soi have the new 2011 150 Gxl v6 petrol with dual tanks. I understand I only have one filler so when I fill one I fill both confirmed by the 150 liters I put in. Sofar so good.

Now every other dual tank system I have ever in countered has a manual switch to swap to sub etc, dual gauges or a gauge that like theb90 - 120 series jumps from half back to full as we swap tanks automatically.

But this system confounds me, if I'm reading every piece of information I have found the system works like this: (please confirm/ deny/explain)

As I see it, when my tank starts to empty the sub automatically flows through, as the fuel gauge reads from the main tank, when it reads half a tank it actually means I have had all my sub drain through and am now left with only half in main tank. If so this is false hope / reading as I believe I have used half of the 150 ie 75 and have 75 left when I fact I only have half main ie 45 liters is this right I don't quiet get it sorry.



Again I have looked but don't quite find an answer that suits my model gxl

[ntp Addicted PP Member Find all posts View Profile Close ntp]

I think the only difference between the previous models and the 150 is the overall tank sizes. As I understand it, the fuel transfer system is basically the same.

Some previous threads that talk about this:

150 GXL fuel tanks

Fuel warning light

Duel (sic) fuel tank issues

[Richoson Avid PP Poster! Find all posts View Profile Close Richoson]

Hi Fierce

Can you get more than 120lts on when the fuel gauge shows empty.

See ya on the tracks, Richo.


Sent from Richos iPhone using Tapatalk

[fierce Lurker Find all posts View Profile Close fierce]

Cheers everyone, when I searched none of those links came up or the links that they in turn lead to.

So anyway I kept expecting there to be some change in the gauge, Esspeciallu when everyone keeps telling me I should be getting 12-13 hundred kms out of a full tank but on the fuel warning light coming in imagine my suprisr when I've only done 900 km. But after reading these threads I pushed past the fuel light today for the first time today and got a further 90 kms before the cruise range hit zero and then another 75 before I chickened out and filled up. So that's about 1100 + kms so guess I'm actually on about track, also meaning my gauge must read pretty true, except when empty comes up a will have some left in reserve.

[wooley Avid PP Poster! Find all posts View Profile Close wooley]

I don't trust either the gauge or the km to empty computer anymore; the other day I did 800km on less than a 1/4 of a tank, which still only dropped to half after 1100km (the next morning was reading more accurately) on another tank i filled up and my range to empty was 700 odd km which went down about 5km an hour until I had done 5-600km then almost started working.

Two problems I cant understand or explain. Will see how goes with 3-4 more tanks this week.

[fourbyfour Junior Member Find all posts View Profile Close fourbyfour]

I filled up last week with the computer telling me I had 73 km to empty, I just barely got 120 litres in, meaning about 30 litres is left in the reserve. I wonder though whether scanguage would give a more accurate reading and by how much it differs

[stevensr34 Senior Member Find all posts View Profile Close stevensr34]

Fierce,

So, to answer your original question, (for future reference when the next person searches for this topic), the answer by LeighW pretty much sums it up:

Fuel is pumped from the main tank to the injector pump, excess fuel flows back from the injector pump
to the main tank the via aux tank. Note the fuel does not actually empty into the aux tank
simply goes in and out through a coil, I assume this is to heat or cool the fuel that's in
the aux tank for some reason, most likely heat as if the aux is empty then it wouldn't
cool the fuel going through.

The the fuel returning from the injector pump via the aux passes through a venturi in the main
fuel tank. The venturi is used to suck fuel from the aux into the main. So basic answer is fuel returning
from the injector pump drives a venturi effect which is used to suck fuel from the aux, there is no
actual pump between the two tanks.

[ntp Addicted PP Member Find all posts View Profile Close ntp]

So, to answer your original question, (for future reference when the next person searches for this topic), the answer by LeighW pretty much sums it up:

Or just merge the said threads so that we don't have multiple lines talking about the same thing, just in slightly different ways.