In Los Angeles, the garden snail Theo dreams on being the fastest racer in car races and worships his idol, the champion Guy Gagné, who has won the Indianapolis 500 several times. His brother Chet protects him most of the time from daring situations caused by Theo. When Chet rescues Theo from a failed attempt of recovering a prize tomato, Theo leaves the garden feeling humiliated. Soon he is accidentally sucked by the supercharger of a racing car and he drowns in the nitrous oxide injected to speed up the car. On the next morning, Theo finds that he has achieved speed power. When a crow picks Chet from the garden, Theo pursues them and rescues his brother. However they are captured the taco truck driver Tito and brought to a snail race. When Tito sees the performance of Theo, a.k.a. Turbo, in a race with the other snails, he decides to enter Turbo in Indianapolis, despite the disagreement of his brother Angelo. But his neighbors share the entrance expenses and they head to Indianapolis. Who will win the Indy 500?