|This article is about a/an device in GoGo Sentai Boukenger.|
The Parallel Engine is a machine originally theorized by the Renaissance genius Leon Giordana for the creation of a massive amount of energy. Though merely part of his notes of future technology of the time, it would eventually be discovered by the Search Guard Successor Foundation, an organization who would utilize the notes as the basis of the development of technology for their purpose of finding and collecting dangerous Precious artifacts. The Parallel Engines were created by the SGS and used for the building of various vehicles for Precious acquisition. The engines would also be tied to a special suit developed to utilize their energy for human usage to allow for further search and management of Precious and those who would use them for evil purposes, making these users the "Boukenger". The power of the Parallel Engines, though, are enough to force further training and manipulation for the management for human usage due to the physical harm long-term and high intensity usage causes.
Due to the gaining of an equivalent "Gordom Engine" by the Negative Syndicates, the SGS were forced to develop a more powerful Neo-Parallel Engine in order to counter them and continue to use the powers of the Boukenger against the inverse energy utilized by the evil engine. While Bouken Silver's was already ready as his Bouken Vehicles have just been completed, initially the other five were at a disadvantage until their vehicles were refitted with the new Neo-Parallel Engine design. After Arch Priest Gajah evolved into his final form and drained the energy from the Precious in Siren Builder, Mr. Voice temporarily deactivated the Boukenger powers to remodel the Neo-Parallel Engines in the 18 Bouken Vehicles so Gajah could not siphon off their energy again.