Do tugs need extra fuel for when they're tugging, or is their range accurate?

[porcuspine (OP)]

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?

[Froggiest1982]

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.

[Migi]

If you have the tug and the cargo built, you can see the range in game if you go to the Naval Org window, open the fleet and select the ship (the tug, not the payload).
It should switch automatically to the Ship Overview tab, Ship Design Display sub-tab. The 2nd box shows the range based on the fuel available and current payload.

[skoormit]

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.

[porcuspine (OP)]

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.

[Density]

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.

[bankshot]

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.

Since large fuel tanks are fairly lightweight my tugs ARE my tankers.  I also put one cargo shuttle and a large maintenance storage bay on them so they can resupply as well as refuel. 

[ArcWolf]

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.