Chuggington (2008)

Season 2: Episode 9

Dr Ling is experimenting with a new invention that can help chuggers increase their speed - the Booster! Brewster helps her to test it. The new booster makes him go super-fast, but it has some terrible side effects. Brewster gets a lot of attention and loves being thought of as a speedy engine, so he says nothing about the problems.