在《变形金刚》系列电影中，擎天柱的片尾对白随着剧情的发展而有所变化，但始终贯穿着自由、正义和团结的主题。以下是擎天柱在不同电影中的片尾对白：

《变形金刚1》

"I am Optimus Prime, and I am here to summon all the Autobots scattered across the universe. We are here on Earth, waiting for you."

《变形金刚2》

"We were once lonely beings, feared by humans. But now we have found our home, found our brothers. We are free, we are just."

《变形金刚3》

"Our home planet is dead, but our race lives on. In this universe, we are no longer alone."

"We will stand with those who fight for freedom, never surrender."

《变形金刚4》

"We have fought for our home across hundreds of planets and years. Now we have come to Earth, and we will protect it as if it were our own."

"When you look up at the stars, remember one of them is my soul. Please protect this family, the Autobots, as they protect you and their future."

《变形金刚5》

"Deep within the Earth lies a dangerous secret. There is much on this planet that is beyond our sight. I call upon all Autobots, it is time to return to our homeland."

这些对白不仅表达了擎天柱对自由和正义的坚定信念，也体现了他作为领袖对同伴们的关爱和对地球的保护之心。