Give the 1.25m LF tank the proper amount of fuel.

[Frozen_Heart]

This is a minor problem and pretty easily fixed. The 1.25m LF tank holds a completely wrong amount of fuel for its size.

These are the current stats.

Mk-1 LF fuselage: LF - 160

FL-T400 Fuel Tank: LF - 180 Ox - 220

Not only does the rocket fuel tank hold more LF than the dedicated tank, it holds the oxidiser as well.

It should probably hold somewhere between 200 and 300 LF. Accounting for its higher impact tolerance.

[Bill Phil]

What about the mass?

[sal_vager]

Yeah the aircraft tank is very much lighter, it's not supposed to be only full of fuel.

[bartekkru99]

What I would suggest is making realistic jet engines split into a compressor, combustion chamber and turbine with a nozzle, or at least making existing ones much longer, so there's not that much room to store fuel and then making existing tanks more capacious.