Maybe I misunderstand something, but extra fuel tank for X-COM Aircraft adds very little amount of fuel. Interceptors have 1000 units of fuel by design
(look here), and the fuel tank adds 20 more
(here). It is a tiny gain of 2%! Very little and 100% useless.
What if the tank can be attached to a mudranger, the craft with the minimal fuel capacity? The gain will be 20/140=1/7, not bad, almost useful.
Maybe the fuel tank addition must be 20%, not the flat 20 units?
