This will probably come up a lot when 3.0 drops, so here's your guide to which one to pick in order to maximise jump range.

To recap:

__Mass manage__r: gives you a 4% increase to your optimised mass. This multiplies with any base optimised mass increase you have from the increased range blueprint.

__Deep charge__: gives you a 10% increase in max fuel per jump.

Tl;dr - mass manager is best for larger FSD classes; deep charge is best for smaller ones. The break-even point is a class 5 FSD; in that case choose mass manager because it will be more fuel efficient.

__The maths__
If like me you like equations almost as much as you like playing Elite, read on for the details...

We begin with the hyperspace fuel equation:

https://i.imgur.com/T5UmyGZ.jpg
Where:

- f is the fuel required (tons)
- d is the distance to be travelled (light years)
- M_ship is the mass of your ship (tons)
- M_opt is the optimised mass of your drive (tons)
- l and p are constants defined by the rating and class of your drive, respectively

This governs your maximum range, because your drive cannot consume an unlimited amount of fuel per jump. This is why, if you select a system beyond your maximum range and attempt to jump, the error you get is 'max fuel exceeded'.

Rearranging, we get

https://i.imgur.com/VEyVV90.jpg
Now we can see more clearly the factors affecting our maximum range. It scales linearly with optimised mass (irrespective of anything else), but any multiplier of maximum fuel is raised to the power of 1/p. The question, therefore, is which gives the higher multiplier: a straight 1.04 (Mass Manager) or 1.1^(1/p) (Deep Charge)? This calls for a spreadsheet! I like spreadsheets.

**FSD class** | **p** | **1.1^(1/p)** |

2 | 2 | 1.049 |

3 | 2.15 | 1.045 |

4 | 2.3 | 1.042 |

5 | 2.45 | **1.04** |

6 | 2.6 | 1.037 |

7 | 2.75 | 1.035 |

You can now see that they give the same result for a class 5 FSD. Mass Manager would actually have a tiny advantage because M_ship includes the mass of the fuel needed for the jump, but it's already the best choice because it is more efficient.