|This article is about a/an mecha robo in Engine Sentai Go-Onger.|
|Sentai Show:||Engine Sentai Go-Onger|
|First Appearance:||Siblings Battle!?|
|Number of Episode|
Full list of appearances
|Length:||40.5 to 77 m|
|Width:||28.6 to 43.6 m|
"Engine Fusion - Mission Start! SeiKuu-O Tune up! Go-on!"
Attacks are Toripcutter (Toripukatta), Jetras Boomerang (Jettorasu Bumeran), Jetori Turbulence (Jettori Tabyuransu), Seikuu Sonic (Seiku Sonikku) and its finisher is Seikuu Impulse (Seiku Inparusu).
See also: SkyRev Megazord
"G9 Formation - Engine Fusion! Engine-O G9 Tune up! Go-on!"
Engine-O G9 (エンジンオーＧ９, Enjin'ō Jī Nain), known as the "Earth and Air Reigning King" (空と大地に君臨する王, Sora to Daichi ni Kunrin suru Ō), is a combinations of Engines 1 to 9, piloted by the five Go-Ongers and the Go-On Wings team. The combination is simple, with Engines Toripter and Jetras landing on Engine-O G6's shoulders and Engine Jum-bowhale attaching to its back, Toripter's tails forming "goggles" for Speedor and Jetra's rudder and elevators form the helmet. Its finisher is G9 Grand Prix.
- With Engine Gunpherd, SeiKuu-O becomes SeiKuu-O Gunpherd (Seikuo Ganpado), Toripter's turrets and the Gunpherd Gun in its Guntori Gunfire (Gantori Ganfaiya).
- With Engine Birca, SeiKuu-O becomes SeiKuu-O Birca (Seikūō Baruka), using the Bircutter and Jetras's fangs in its Birtras Torahawk (Barutorasu Torahōku).
- Engine-O G9 combines with Engine Gattai Kyouretsu-O to form Engine-O G12.
- The Samurai Formation 23 is a formation between SamuraiHaOh and Engine-O G12 where Engine-O G9 breaks off to join an attack formation.