This paper studies how effective an incremental change in the price of fuel, a proxy for fuel carbon tax, is in reducing the emission intensity of road transportation in Brazil through panel analysis at the federative unit level from 2010 to 2020, after offering descriptive insights into Brazil's automotive fuel market with respect to its products, actors, and external factors. The paper postulates multiple variations of panel analysis models and focuses on dynamic two-way fixed effects models based on statistical results. The findings show that (1) the price of diesel has the most significant and robust impact on reducing emission intensity
(2) the short-run and long-run elasticities of the price of diesel are -0.74 and -2.06, respectively
and (3) both entity and time effects are significant, with the year of 2020 having a consistent effect in reducing emission intensity across the estimated models.