Wankel engines, while praised for their simplicity and high power-to-weight ratio, are not widely adopted due to significant drawbacks such as high fuel and oil consumption, complex manufacturing challenges, and thermal issues. The engine's design leads to incomplete combustion and high hydrocarbon emissions, making it less viable in today's fuel-conscious market. Mazda utilizes Wankel engines in sports cars but still faces challenges with fuel efficiency and emissions. Additionally, issues like carbon buildup can cause engine seizure if not properly managed. Despite Mazda's advancements and patents, the overall performance and efficiency of Wankel engines remain inferior to conventional internal combustion engines, leading to their limited use in the automotive industry.