The presence of violence (or terrorism) caused by the terrorist sect Boko Haram prompted the Nigerian Government to proceed with the closure of its border with the northern part of Cameroon. This decision caused the rise in the price of adulterated fuel commonly known as "zoua zoua" in the local dialect, which represents about 75% of the market for fuel consumed in the northern part of Cameroon. In this context, the main objective of this study is to analyze the behavior and sensitivity of the fuel-gasoline consumer in the city of Maroua. The data used for this study come from a survey carried out by means of a questionnaire among 300 motorists with engines consuming only gasoline in the city of Maroua during the month of July 2019. This choice is justified by the 'unavailability of aggregate data on the volumes of fuel consumed in the city of Maroua and the concern to guarantee the size of the target sample. To construct the sample, the study used the non-random sampling method, in this case the quota method. Comparison of means tests on independent samples are used on cross-sectional data. The results of the estimations obtained on primary data show that, ceteris paribus, the consumer turns to the informal sector and only turns away from it when the price of adulterated gasoline increases.