Problems with Legacy or Modern Fuel Systems

I’m not going to criticize, but simply observe… The Legacy system does
not display more than 5 tanks in the simulation window, while there is the
possibility of using up to 11 tanks in the flight_model.cfg…! Why is that?
The Modern system allows you to display the amount of fuel available in
the tanks with the variables FUELSYSTEM TANK QUANTITY:index or FUELSYSTEM TANK
WEIGHT:index or FUELSYSTEM TANK LEVEL:index. These variables are settable…!
In my example, I use 7 Tanks defined Tank.1, Tank.2… Tank.7. I can see the
QUANTITY:2)… (A:FUELSYSTEM TANK QUANTITY:7). But when I want to modify the
content of the tanks by (>A:FUELSYSTEM TANK QUANTITY:1), (>A:FUELSYSTEM TANK

  • tank.1 is modified by the command (>A:FUELSYSTEM TANK QUANTITY:6),
  • tank.2 is modified by the command (>A:FUELSYSTEM TANK QUANTITY:7),
  • tank.3 is modified by the command (>A:FUELSYSTEM TANK QUANTITY:8)… (!!! while I use only 7 tanks…),
  • and I can’t modify at all the fuel quantity for tanks 4 to 7…! So what is going on…?

Thank you for taking the time to address these issues! Best regards,

Hello @ChrisSMS When you say “simulation window” you mean the fuel panel? If
so, I think it was just an issue with UI not being refreshed correctly on a
Save&Resync.; I no longer have the problem on the SU10 flighting build, can
you check it’s working as expected for you too? Regarding the indexing system.
That’s something we’re looking to change with SU10. The new fuel system uses
the legacy indexing system, using the position of the tank to determine the
index. We will fix this in a later flighting build and when using the latest
fuel system version, you will now use the index defined in the cfg. Regards,

Hi Sylvain, Yes, I did mean the fuel system window…! I will check what
happens if I increase the number of tanks in SU10: I had opted for a solution
of grouping the tanks so that they are visible in the said window… I’ll let
you know as soon as I can do the tests. And thanks for taking into account my
request for the new fuel system…! Greetings, and good flights! Chris

The change on SU10 is not available with the flighting yet. It probably will
with the next build (we will update the flighting build before the final SU10

OK Sylvain…! **** But I just did a test for the number of tanks displayed
with the old fuel system: it still doesn’t work! If all the tanks are used,
they are all displayed. But in my case, I use CENTER 1 + LEFT MAIN + RIGHT
not displayed!

That’s right, I tested by enabling all tanks but the UI is incomplete when
having some tanks only. Simvars are matching what’s defined in the CFG though
so I expect it’s only a UI issue. I will file a bug about this. Thank you for
reporting it. :slight_smile: Regards, Sylvain

@FlyingRaccoon is wrong indexing issue still exists? as I am experience same trouble with SimConnect.
And what is most annoying - some tanks does not respond on fuel quantity set.