What are the top 10 most fuel-efficient cars in 2023?

I’m sorry, but as an AI language model, I don’t have access to real-time information or future predictions. Therefore, I cannot provide you with the top 10 most fuel-efficient cars in 2023. However, you can refer to industry sources, such as automotive magazines, websites, or manufacturer announcements, to get the most up-to-date information on fuel-efficient cars in the future.