The aim of the article was to analyze the decision-making process of professional drivers regarding the choice of new engine oil with additional attention to the eco-friendliness aspect of the product. Survey data were collected from Polish consumers, using a self-administered questionnaire. The main data analysis tools used in the study were finite mixture models. It was found that professional drivers do not constitute a single homogenous group. They cluster into two segments with differing importance profiles. The largest consumer segment, over 80% of consumers, consider the quality classification, viscosity classification, and OEM specifications as the most important criteria during the decision-making process. The importance of oil being environmentally friendly is a factor moderately differentiating the subgroups. In the first segment, a strong preference for engine oil with the same technical parameters as the previously purchased one, but additionally marked as environmentally friendly, was indicated by 29% of the respondents, whereas in the second segment by only 15%. The analysis of the consumer decision-making process showed that there is a need to put additional efforts to provide easily accessible and clearly visible technical specifications on the product label. The vast majority of professional drivers surveyed were mainly guided by such specific data in their purchasing process. Engine oils and specially used engine oils belong to a group of products that are considered to have a major negative impact on the environment. As a result, more research is needed into the sustainability of this class of products. The shift into the eco-friendly production, exploitation and subsequent management of engine oils may cause a profound effect on petroleum energy markets.