Engine Gattai Engine-O

"Engine Fusion! Engine-O Tune up! Go-on!"

Engine Gattai Engine-O (炎神合体エンジンオー, Enjin Gattai Enjin'ō) is formed when Speedor, Buson and Bear RV combine. Referred to as the "King of Engines". It's main finisher is Go-on Grand Prix (ゴーオングランプリ, Gōon Guran Puri), charging the enemy at fullspeed with its Go-on Sword (ゴーオンソード, Gōon Sōdo), landing the deathblow as it moves past. It has the V Shield (Ｖシールド, Bui Shīrudo). With GunBir-O and SeiKuu-O, it can perform Go-onger Storm (ゴーオンジャーストーム, Gōonjā Sutōmu), Triple Punch (トリプルパンチ, Toripuru Panchi), and Grand Prix Festival (グランプリフェスティバル, Guranpuri Fesutibaru). It is composed primarily of Speedor, Bus-on, and Bear RV, but can receive power-ups by performing Engine Armaments (炎神武装, Enjin Busō):

Other Combinations

 * With Birca, Engine-O becomes Engine-O Birca (エンジンオーバルカ, Enjin'ō Baruka), using the Bircutter in its Bircutter Slash (バルカッタースラッシュ, Barukattā Surasshu) attack.
 * With Gunpherd, Engine-O becomes Engine-O Gunpherd (エンジンオーガンパード, Enjin'ō Ganpādo), using the Gunpherd Gun in its Gunpherd Gunfire (ガンパードガンファイヤー, Ganpādo Ganfaiyā).
 * With Jetras and Toripter at the same time, Engine-O becomes Engine-O Jetripter (エンジンオージェットリプター, Enjin'ō Jettoriputā), using its right arm's Toripter Rotor (トリプターローター, Toriputā Rōtā) for defensive/offensive attacks while its left arm is used as the Jetras Bow (ジェットラスボウ, Jettorasu Bō) in the Jetori Bullseye (ジェットリブルズアイ, Jettori Buruzuai) attack.
 * When armed with Jetras only, Engine-Oh becomes Engine-O Jetras (エンジンオージェットラス, Enjin'ō Jettorasu). It fires the Go-On Sword with Jetras' bow.
 * Engine-O combines with Engine Gattai GunBir-O to form Engine-O G6, which in turn combines with Engine Gattai SeiKuu-O to form Engine-O G9, and further with Engine Gattai Kyouretsu-O to form Engine-O G12.