So, does that mean that they are lost? No just calling out the RAC to bring a can of fuel?
When a ship runs out of fuel, it can still warp but only at 33% speed - which means it takes forever just to limp to the nearest system.
This is why I was furious with how the game used to work: a fuel tanker would warp to the crippled ship to deliver fuel, but since the supposedly empty ship could still warp, the tanker would invariably miss it and try to catch up again. Repeat
ad nauseum until both ships arrive at the destination where fuel is probably waiting anyway. This effectively tied up two ships instead of one and it's absolutely baffling that the game launched with that behaviour.
Supposedly tankers are a lot more sensible now, and favour fleets instead of lone ships. I've only just got tankers up and running in my new game so I haven't tested it fully yet.
I'd prefer that ships with no fuel are simply unable to move. Not only does it make more sense, but it also means any tanker can easily assist it.
I'd further prefer that ships don't run out of fuel for no good reason. In this case my explorers are surveying systems until they're at 0%, and only then does it occur to them to go find some more fuel.