Nearly every major carmaker in the world is working on some sort of alternative combustion engine technology, be it ethanol or hydrogen fuel, advanced diesel engines or the advanced hybrid petrol solution known generically as HCCI (Homogeneous Charge Compression Ignition), or as Mercedes has branded it, DiesOtto. The basics involve use of diesel engine principles in petrol-fueled engines for a combination of greater power output and fuel efficiency than either traditional petrol or diesel solutions.

In this video, Dr. Günter Karl explains the process in detail, with the aid of a cutaway engine. As Dr. Karl points out, the technology is currently still in the experimental stages. Test engines have been fitted to a number of cars, however, including the F700 concept and an S-Class, the latter achieving 39mpg (6.0L/100km) and 238hp (175kW) from a mere 1.8L engine. Two-stage turbochargers, direct injection and controlled auto-ignition make for a very interesting use of four minutes.