Ultimate Energy Engine

The Ultimate Energy Engine is an object that appears in the Sonic the Hedgehog series. It was an extremely powerful and clean engine developed by Donpa Motors to usher in a new era of prosperity and cooperation throughout the universe. However, it was targeted by Dr. Eggman, who sought to use it for his own nefarious purposes.

Appearance
The Ultimate Energy Engine's exact appearance is unknown. However, it is seemingly small enough to fit inside Dr. Eggman's monster machine.

Powers and traits
The Ultimate Energy Engine is described as the fastest and most powerful engine in the universe, suggesting it provides power on a cosmic scale. Dr. Eggman himself theorized that if he used it to power his Death Egg, he would command an invincible force of his own. It is powered by nothing but the inherent strength of teamwork, making it a clean source of energy.

Team Sonic Racing
In Team Sonic Racing, the Ultimate Energy Engine was a secret project developed by Donpa Motors for philanthropic uses. When completed, it could be used to usher in a new era of prosperity and cooperation throughout the universe by revolutionizing transportation, fueling new industries, and reducing pollution using only the strength of teamwork.

Eventually, all the Ultimate Energy Engine needed for completion was sufficient information on enough accumulated Ultimate Team Energy. Wanting to produce the best results with the aid of the bests, Dodon Pa got the best racers he could find across space and time to compete in a team-orientated Grand Prix of his, believing they could provided better teamwork results than his staff and resources at Donpa Motors could. However, he kept his motives hidden to perserve the Ultimate Energy Engine's secrecy. After each race, Dodon Pa would then sent the information he gathered from the racers' teamwork to his research and development, who used it to work on the engine.

Learning of the Ultimate Energy Engine, Dr. Eggman heard of its capabilities from Dodon Pa. Realizing he could use it to make his Death Egg invincible, Eggman hired Zavok to steal it. However, Zavok was unable to find it, as it was apparently kept in an unknown location. Later, the rest of Dodon Pa's racers learned of the Ultimate Energy Engine from Dodon Pa after discovering his background and his motives for hosting the Grand Prix. Knowing it was for a good cause, the racers agreed to keep competing.

Growing impatient, Eggman decided to kidnap Dodon Pa and make him hand over the Ultimate Energy Engine. Dodon Pa explained, however, that the engine was worthless to him, as enough Ultimate Team Energy had yet to be accumulated to complete it. Furthermore, by kidnapping Dodon Pa, Eggman had made the racers stop racing, thus cutting off the energy needed to complete the Ultimate Energy Engine. To remedy that, Eggman made the heroes who came after him to save Dodon Pa face him and his henchmen in a series of races, thereby producing the Ultimate Team Energy needed to finish the Ultimate Energy Engine. Upon its completion however, Eggman stole the engine and installed it into his monster machine to crush Sonic. However, the monster machine eventually went crazy and drove straight into the Final Fortress's energy core, destroying it and the Ultimate Energy Engine.