Transformers 2 AutoBots

* Peter Cullen voices Autobot leader Optimus Prime. He retains his alternate mode of a blue Peterbilt truck with red flame decals. Cullen recorded a voiceover for the opening scene in August 2008, but began the majority of voice work in November.A live action cameo has been written for Cullen.

* Mark Ryan voices Bumblebee, the Autobot who befriended Sam and disguises himself as his fifth-generation Chevrolet Camaro. Ryan also continued his role as stand-in for the robots on set. Bumblebee's voice is still healing and he still uses radio soundbites to express some of his emotions. The filmmakers used the Super Sport version of the 2010 Camaro rather than the concept version. Ed Welburn, vice president of GM Global Design, said the redesigned car emphasized Bumblebee as becoming stronger after having his severed legs reattached in the first film: the new intakes and spoilers show he is a sturdier character.

* Jess Harnell voices Ironhide, the Autobot weapons specialist who transforms into a GMC Topkick.

* Robert Foxworth voices Ratchet, the Autobot medic who transforms into a search and rescue Hummer H2.

* John Turturro voices Jetfire, a former Decepticon who transforms into a SR-71 Blackbird. His wounds and age have made him choose to become an Autobot. He can combine with Optimus, an idea previously seen in the Transformers: Armada series. The writers wanted a geriatric robot, and during scripting they gave Jetfire that personality. Turturro offered to voice the character because he thought it would be a fun part.

* The sisters, three Autobots with feminine appearances and personalities. Whether to explain robotic gender or not was something the writers were unsure about, and it remained undecided until post-production.
o Arcee, a pink motorcycle. Arcee was dropped from the first film as the writers felt there was not enough time to explain her "gender", although she and several other female Transformers appeared in the first film's toy line and tie-in comics.
o Chromia, a blue motorcycle. She is Ironhide's girlfriend.
o A purple motorcycle.

* Mudflap and Skids, respectively a red Chevrolet Trax and green Chevrolet Beat. Mudflap is very hyperactive, while Skids believes himself to be the smarter of the two and tries to come across as mature, but nevertheless appears unable to keep quiet. Bay compared the message of the bumbling but heroic characters to the story The Little Engine That Could. He chose the Beat and Trax for the Autobot twins because he thought those two small cars looked good together. Ed Welburn added when they had designed the cars before Bay selected them, the "character" they wanted to bring to the concepts was a sense that small cars could be as cool as large ones. The Twins start the film by combining into an ice cream van.

* Sideswipe, a silver Chevrolet Corvette Stingray Concept.

* Jolt, a blue Chevrolet Volt. Jolt was a last-minute addition to the cast as General Motors, the film's car supplier, wanted to promote the Volt. The writers had already wanted to include the car in the script before the Writers Guild strike, so they had to work out a character that would fit well within the Autobot team afterwards and convince Bay to approve the addition. Welburn was pleased the Volt's character was christened Jolt by the filmmakers, as it reflected that car's design "character".

* Wheelie, a small radio-controlled monster truck. Wheelie initially serves the Decepticons because he is frightened of them, so he joins the Autobots.