Steam Engine is an ability in the Pokémon series with unique and strategic benefits. When a Pokémon with this ability is hit by a Fire-type or Water-type move, its Speed stat sharply increases, equivalent to a +6 boost, which maximizes the Pokémon's Speed stat. This massive increase can turn the tide of a battle, allowing the Pokémon to outspeed nearly any opponent regardless of prior differences in Speed.
Introduced in Generation VIII, Steam Engine is most famously associated with the Rock/Fire-type Pokémon, Coalossal. The ability synergizes well with Coalossal's typing and movepool. For example, players often use moves like Surf or Aqua Jet from a partner Pokémon in double battles to trigger Steam Engine, propelling Coalossal's Speed and simultaneously activating its Weakness Policy, further boosting its offensive stats.
Another interesting aspect of Steam Engine is that it offers Coalossal a tactical advantage despite its dual weakness to Water-type moves. Normally, Water-type moves would severely damage Coalossal,