Theo (Ryan Reynolds), self-christened Turbo, is a garden snail out of pace with his brethren. He idolises human racecar driver Guy Gagne (Bill Hader), and is given to fanciful reveries that exasperate his more grounded brother Chet (Paul Giamatti), who helps oversee the snails’ methodical harvest of tomatoes which keeps their community fed. When a freak accident wherein he gets sucked into the nitrous oxide-booster of a drag racer leaves him with super-speed, though, Turbo’s wish actually comes true: suddenly he can speed around as fast as any car.
Turbo is discovered by Tito Lopez (Michael Peña), a taco truck driver and fellow inveterate dreamer who owns a foundering restaurant with his brother Angelo (Luis Guzmán). After a rocky introduction to Whiplash (Samuel L. Jackson) and some snails Turbo makes nice, and Tito discovers his gift. Partnering with the other small business owners (Ken Jeong, Richard Jenkins, Michelle Rodriguez) in their struggling Van Nuys, California, strip mall, Tito takes Turbo on a road trip, to enter him in the famous Indianapolis 500 and let him race against Guy and other human drivers.
With ease and aplomb, Turbo taps into feelings of underdog uplift (“No dream is too big, and no dreamer too small”). Unaddressed questions abound, though (how, prior to a human makeover, did Turbo get painted decals on his shell?), indicating a certain shrugging, slapdash laziness with the concept, or perhaps the result of unmerged draft revisions (director David Soren, Darren Lemke and Robert Siegel share screenplay credit).
Unwilling or unable to exploit for potential comedic effect any gaps in understanding between its snail and human characters (the latter address the former, though they’re never able to hear them speak), Turbo tries somewhat awkwardly to thread the needle between blithe acceptance and astonished celebration of its main character’s gifts; no one ever seems to ask how or why. The result is an unconvincing tone.