This study aims to examine how the Carbon Intensity Index (CII) for vehicle carriers has changed, using data from the EU-MRV database for vehicle carriers in 2022 and 2023. The analysis draws on information from the 2019–2022 International Maritime Organization (IMO) Data Collection System (DCS) report regarding the current fleet’s efficiency and annual carbon intensity. A modified Markov chain is employed to quantify the impact of mitigation measures imposed to improve the energy efficiency of car carriers. The expected likelihood of transitions before the fleet of ships reaches a particular CII state for the first time, as well as the average time it takes to transit from one state to another using a transition matrix, relies on energy efficiency. However, the limited timeframe of the data sample presents challenges in estimating the transition matrix. Many regulatory bodies have started collecting data on ships’ CII rates to obtain consistently reliable data over extended periods. While the short time horizons may affect the interpretation of the results, they do not compromise the fundamental viability of the underlying model.