I'm looking for an average number here, I know there is not one correct answer as there are many parameters to take into account.
Alternatively, I could also use something different, like : how many extra fuel does it take to carry 1kg extra freight from city A to city B.
I guess there is more chance to find empirical data than a perfect answer.
I've found many articles explaining that airlines can save XX€ by removing YY item from the plane, or that it's worth replacing crew books by ipad etc... And it makes total sense that less weight = less fuel required.
But I've not found any details that would allow me to calculate what I need.
Basically, I want to be able to estimate if it's worth replacing an item by a ligther but more expensive one in an aircraft.
The only thing I found so far is this : Weight of fuel required to carry 1Kg additional weight per hour : 0,04 Kg
But I've no idea where it comes from, so I'd appreciate if you could confirm and give some detail.
Ultimately, my goal is to get airlines to switch to ligther stuff so they emit less CO2.
Thanks a lot!