Turbo runs out of fuel too soon.

“Turbo” is the latest animated features to show that it’s not enough to have a cute and clever concept and a great voice cast if you haven’t really got a good story to hang the whole thing on.

It starts brightly enough, with Theo the snail (voiced by Ryan Reynolds) dreaming of being the fastest snail alive, and wanting more from life than the slow-paced existence he has although his daydreaming and lack of attention to his job are a constant embarrassment to his more cautious brother Chet (Paul Giamatti). One day, Theo goes exploring and reaches the freeway where a series of mishaps culminates in him being sucked into the supercharger of a drag racer, infusing his body with nitrous oxide. The next morning, Theo finds he has the power of incredible speed amongst other car-like abilities. When he tries to show off his power, it goes horribly wrong, he and Chet are fired from their jobs and when Chet is snatched by a crow, Theo sets off in hot pursuit. They eventually find themselves at a run down strip mall where Taco truck driver Tito (Michael Peña) captures them both, intending to use them in a local snail racing league. But once he witnesses Theo’s super speed, Tito starts to dream much, much bigger.

The animation is as good as you would expect from Dreamworks and the character design is clever and appealing. When the story focusses on the snails themselves, it’s pretty strong and the human characters, while broadly drawn, are interesting and funny in their own right. It’s when the two worlds interact that the films gets into a little difficulty as everything is accepted too conveniently and despite a willing suspension of disbelief, the sheer unlikeliness of events continues to nag at the back of your mind. It’s also a shame that the interesting premise and characters are eventually wasted on an underwhelming rehash of ‘The Tortoise And The Hare’.

Despite the cast, the colourful and exciting visuals, “Turbo” simply doesn’t manage to get enough traction and all too oftens ends up spinning it wheels, waiting for the inevitable ‘believe in yourself’ ending to triumph. With a cleverer story, this could have been a real animated thoroughbred but as it is, Dreamworks’ snail-based racing caper just feels sluggish.