If my tug has a range of 100 billion km, when it tractors another ship will it still have that range or will fuel use account for the newly added tonnage?

worth noting that this utility program https://aurora2.pentarch.org/index.php?topic=10999.0 has a feature for designing tugs.

Darn so I'm really gonna have to burn 30 million litres of fuel just to tug an orbital habitat one system over, huh? And so many engines just to go 200km/s. . . .

Side note: fuel has become less of a problem after attaching one of my military tankers to the tug fleet whenever it has to tug a long distance.

I prefer to build my OHs on site over tugging those around. You don't even need population at the location to get started (though it is usually quicker with a standard workforce), just a place to land troops and minerals.

If my tug has a range of 100 billion km, when it tractors another ship will it still have that range or will fuel use account for the newly added tonnage?

For a tug design with range R, tugging a ship N times its own size:

The one-way range is R/(N+1). The tug can go that far before running out of fuel.

The round-trip limit is R/(N+2). The tug can go that far, release the payload, and still have enough fuel to return.


For example:
My tugs tend to be around 50kt.
My large stations tend to be around 125kt.
125kt/50kt = 2.5.

Therefore:
The one-way range of my tug while towing a large station is the tug's design range divided by 3.5.
The round-trip range of my tug while towing a large station is the tug's design range divided by 4.5.

If my tug has a range of 100 billion km, when it tractors another ship will it still have that range or will fuel use account for the newly added tonnage?

Fuel consumption will be recalculated based on the tonnage you are tugging.

You can Simulate and predict consumption of the most important elements you are tugging by adding dead weight to your design and seeing what speed you will be moving along with the range.