What is "diesotto"

The Mercedes-Benz DiesOtto is an experimental automobile engine that “is said to incorporate the benefits of a diesel engine, but runs on regular old unleaded.”

Its name is a portmanteau of Diesel and Otto, referring to the Diesel engine, first introduced by German engineer Rudolf Diesel, and the Otto cycle, as a reference to Nicolaus Otto (even though the invention of the gasoline engine is variously attributed to both Nicolaus Otto and Alphonse Beau de Rochas).