Idle trains should not use fuel

If for example, you have a train whose only job is to go between two stations, Filling up at one then dropping off at another, but you've set it so the receiving station isn't requesting any trains if the modules are full, you then end up with a train that's sitting at the Filling station. Now that part is fine and dandy, but my problem is that the train is still using a significant amount of fuel just sitting there, and will then just run out of fuel. Personally I think they shouldn't use any fuel at all, as they are purposefully sitting idle, waiting for a job.

Ok, it does seem like I was mistaking a potential bug for a game feature.
I had one train that was idling on an upwards ramp, and that specific train was draining fuel as it just sat there, it was only when I inspected a different idling train that I realized.
Please disregard this suggestion