Fuel reporting bug?

[Loren Pechtel]

I have a science/mining rocket that is configured in an unusual fashion.  There are 4 outer tanks with engines under them and a central tank without an engine.  The central tank feeds the outer tanks.  I just hopped it to the next biome at the cost of half the fuel as shown by the resource display.  The stack display on the left, however, is showing the fuel bar under the "q"--about a quarter full.

It appears that it's counting the % of fuel available to each engine--which counts that central tank 4 times.

(The odd design is because I was trying to build as short and wide a rocket as possible for landing stability.  As it is I wasn't sure it wasn't going to topple despite SAS and RCS when I landed on a 3% slope.  Finding suitable landing spots in some of the biomes is going to be hard!)

[Plusck]

That is normal behaviour. Each engine searches for fuel, lists the fuel tanks available and then starts pulling from those tanks, backwardish (exact rules on priority for fuel pulling are a touch complicated). It reports its total fuel as the percentage of the total available tankage that contains fuel.

So yes, four engines pulling from one big quarter-full tank plus their own fully-full tank will see a lower percentage per engine available than the total percentage of fuel on the ship.

Edited March 30, 2016 by Plusck

[Snark]

Yep, it's not a "bug" so much as a missing feature.  The engines are greedy and assume that all the fuel belongs to them-- they don't know that "that fuel is not all mine because someone else will also be drinking it."

I know that the natural, instinctive reaction when seeing something like that is a "well, that's dumb, they should fix that"... but the problem is actually a surprisingly tricky one to solve, not least because it requires making some assumptions that could prove true or false depending on future user action.