Two drivers take on Germany's longest autobahn. Driving instructor Dirk Loitz will be driving flat out wherever he can. Ralph Müller is likewise a driving instructor but also a fuel economy trainer. He sticks to the advisory (i.e. voluntary) speed limit of 130 km/h, but reckons he won't forfeit much time. 210 km/h v. 130 km/h. Theoretically, that could put over three hours between the drivers over this distance. But what's the result in practice? What is the impact in terms of fuel consumption? And is it really true that speed limits enhance safety? Drive It! delivers the answers.