Expanded Fission Engine

An EXtended Fission Engine or EX Fission Engine is a Fission Engine made less dense in order to reduce weight.

It follows the rules for XXL Fusion Engines except applying the 1/3 weight (and the corresponding rounding) to the Fission type rather than to the Fusion type. It occupies 6 slots in each side torso for IS and 4 for Clans. Clans don't use regular Fission engines but may mount EX Fission Engines.

A difference is that the Extended Fission Engine only costs 1.25 times as much as the equivalent Fission engine of the same rating.