Chemical, environmental, civil, electrical, aerospace, industrial, mechanical – there are so many forms of engineering. What unites them all is a curiosity for how things work, how different elements can be placed together to form something new. These cars are a wonderful way for the young engineer to experiment and have fun. Each one runs on household items like soda or juice. Different fuels produce different speed results, so it's up to the child to devise the best fuel for his Racer.