The surprising story of the hidden powerhouse behind the globalised world - the diesel engine, a 19th-century invention that has become indispensable to the 21st. It's a turtle versus hare tale in which the diesel engine races the petrol engine in a competition to replace ageing steam technology - a race eventually won hands down by diesel. Splendidly, car enthusiast presenter Mark Evans gets excitedly hands on with some of the many applications of Mr Diesel's - yes, there was one - original creation, from vintage submarines and tractors to locomotive trains and container ships. You'll never feel the same about that humble old diesel family car again.