For several years, car manufacturers have significantly reduced the noise levels of diesel engines. This success brings a new challenge: how and in which driving situations is it possible to improve the sound quality of diesel engines in cars towards a higher customer appreciation. It is well established that the sound quality of gasoline engines is preferred to diesel engine sounds. The aim of this work, that focuses on the sound perception of diesel engines, is to explore positive characteristics of this type of engine sound in the listeners’ mind. This paper presents the study in which we identified those driving situations where actually the typical diesel sound develops its proper characteristics. Typical driving situations (urban, rural, highway, etc.), for three different diesel engine classes (3, 4 and 6-cylinders) and different brands of cars are presented to listeners. Their task is to rate the dieselness of twelve sounds on an eleven-point scale. The results from this study, that help to improve the understanding of characteristic situations of diesel engine sounds, will be detailed and discussed in this article.