This dissertation aimed to identify the level of understanding of two different audiences in relation to the type of communication used in automotive lubricants oils packages. The use of technical language and expressions in English is a challenge for the correct interpretation of information, not only for the functionally illiterate consumers, but also for those who have difficulty with this type of communication. The marketing theories have been developed based on the premise that consumers are literate, which really becomes a problem, because approximately one third of the population is considered functionally illiterate. The research was inspired by the S-TOFHLA test, which was developed to assess the level of understanding of individuals in relation to the language used in healthcare. A questionnaire was developed using the cloze technique, which consists in filling in the blanks with a proper word. The results suggest that the public surveyed have different levels of understanding according to their level of education and income, and underline the need for marketing communication become more sensitive to the level of literacy of its target market.