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 EX Fission Engine only costs 1.25 times as much as the equivalent Fission engine of the same rating.

The minimum weight for Extended Fission Engines is 1.75 tons (if using fractional accounting), or 2 tons (if not), compared to the 5 tons of regular Fission engines.