In the vibrant suburban San Fernando Valley, nestled within a tomato garden in Van Nuys, resides Theo, who famously calls himself Turbo. This spirited garden snail harbors an unwavering dream of becoming a race champion, inspired by his idol, the legendary five-time Indy 500 winner, Guy Gagné. However, Turbo's fervor for racing sets him apart from his cautious snail community, ultimately branding him as an outcast and a source of embarrassment for his older brother, Chet.
An unexpected turn of events unfolds when Turbo, during a perilous quest to retrieve a fallen tomato, nearly meets his end beneath a lawnmower. This incident propels him onto a freeway where he admires the speed of the traffic. In a moment of pure yearning, he wishes upon what he believes to be a star—an airplane soaring above—that he could possess incredible speed. Out of nowhere, a wild twist of fate occurs when he finds himself engulfed in the supercharger of a Chevrolet Camaro, merging his very essence with nitrous oxide. Upon regaining consciousness, Turbo discovers that he has acquired astonishing superspeed and remarkable traits akin to a high-performance vehicle.
However, his initial attempts to showcase his newfound powers result in chaos—he crashes into a child's tricycle and tears through the garden where fellow snails labor, leading to both him and Chet being dismissed from their jobs in the garden crew. Following this mishap, Chet expresses his frustrations over Turbo's reckless behavior. Things take a dangerous turn when Chet is snatched by a crow, but Turbo springs into action, rescuing him at a rundown strip mall, aptly named Starlight Plaza.
Here, the brothers are captured by Tito Lopez, a taco truck driver who hosts a snail racing event with his crew. Turbo's extraordinary speed secures him an incredible victory during the race, leaving both the humans and snails in awe, thus earning him the respect of the local snail community, especially from the charismatic Whiplash. Despite this newfound fame, Chet remains reluctant to accept his brother’s transformation and wishes for him to revert to his normal self. Tito, determined to rejuvenate Starlight Plaza, aims to make Turbo the main attraction, but his aspirations are met with skepticism from his brother, Angelo.
In an engaging series of events, the snails devise a clever plan to draw in crowds, leading to a significant boost in business. Capitalizing on this opportunity, Turbo persuades Tito to enter him into the prestigious Indy 500 as a competitor. After initially being denied entry, a serendipitous encounter with Guy Gagné allows Turbo to demonstrate his remarkable speed, ultimately qualifying for the race by achieving a staggering 226 mph, earning him viral fame across social media and compelling the CEO of IndyCar to reluctantly accept him as a participant.
The night before the big race, a heated confrontation with Chet becomes an emotional high point, as Turbo's brother struggles to acknowledge his sibling's dreams. Sneaking out that night, Turbo meets Gagné, who reveals a cynical side that shatters Turbo's confidence. The race day arrives, and amid the chaos, a young spectator inadvertently traps Chet, providing him a front-row seat to the exhilarating event. As the race kicks off, Turbo finds himself lagging behind more seasoned racers. However, encouragement from Whiplash and his crew prompts him to rethink his approach, leading to his gradual ascension through the ranks.
Despite these gains, Gagné resorts to unsportsmanlike tactics, jeopardizing Turbo's progress and ultimately damaging his shell. In a gut-wrenching moment of defeat, Turbo retreats into his shell, longing for the support he once had. Yet, witnessing his brother's despair ignites a newfound determination within Chet—he escapes his confines to rally the crew, urging Turbo to persevere.
Inspired by his brother's transformation, Turbo re-enters the race. In a thrilling showdown, Gagné attempts to eliminate him, but through quick thinking and sheer will, Turbo clinches a narrow victory by performing an impressive tuck and roll maneuver. Following this incredible win, Starlight Plaza flourishes, transforming into a bustling hub where snail races become a prominent attraction. Turbo’s fame revitalizes the businesses, and each snail receives technological enhancements for their shells. In a heartwarming conclusion, Turbo's shell miraculously heals, and he stands ready to race once more.
As a delightful mid-credits scene plays out, we see one of the snails from the garden finally find the ability to tuck into his shell—only to comically realize he has grown too large to emerge from it.
