## Cars with Wankel Rotary Engine
### Introduction
The Wankel rotary engine is a unique and unconventional type of internal combustion engine that has been used in a limited number of production vehicles over the years. Unlike traditional piston engines, which use a reciprocating piston to convert the energy of combustion into rotational motion, the Wankel rotary engine uses a triangular rotor that spins within a figure-eight shaped combustion chamber. This design offers several advantages over traditional piston engines, including smoother operation, higher power output, and a more compact size.
### History of the Wankel Rotary Engine
The Wankel rotary engine was invented by German engineer Felix Wankel in the early 1950s. Wankel’s goal was to create a more efficient and compact engine than the traditional piston engine. After several years of development, Wankel’s engine was first used in a production vehicle in 1964, the NSU Spider.
### Advantages of the Wankel Rotary Engine
The Wankel rotary engine offers several advantages over traditional piston engines, including:
* **Smoother operation:** The Wankel rotary engine has a very smooth and quiet operation, due to the lack of reciprocating parts. This makes it ideal for use in sports cars and other high-performance vehicles.
* **Higher power output:** The Wankel rotary engine can produce more power than a traditional piston engine of the same displacement. This is due to the fact that the Wankel engine has a higher surface area-to-volume ratio than a piston engine, which allows for more efficient combustion.
* **More compact size:** The Wankel rotary engine is more compact than a traditional piston engine, which makes it ideal for use in small vehicles.
### Disadvantages of the Wankel Rotary Engine
There are also some disadvantages to the Wankel rotary engine, including:
* **Lower fuel efficiency:** The Wankel rotary engine is less fuel efficient than a traditional piston engine. This is due to the fact that the Wankel engine has a higher surface area-to-volume ratio than a piston engine, which allows for more heat loss.
* **Higher emissions:** The Wankel rotary engine produces more emissions than a traditional piston engine. This is due to the fact that the Wankel engine has a lower compression ratio than a piston engine, which allows for more unburned fuel to escape from the combustion chamber.
* **Reliability issues:** The Wankel rotary engine has a reputation for being less reliable than a traditional piston engine. This is due to the fact that the Wankel engine has a more complex design than a piston engine, which makes it more susceptible to wear and tear.
### Cars with Wankel Rotary Engines
The Wankel rotary engine has been used in a limited number of production vehicles over the years, including:
* **NSU Spider (1964-1967):** The NSU Spider was the first production vehicle to use the Wankel rotary engine. It was a small, sporty car that was produced in limited numbers.
* **Mazda Cosmo (1967-1972):** The Mazda Cosmo was the first Japanese car to use the Wankel rotary engine. It was a high-performance sports car that was produced in limited numbers.
* **Mazda RX-7 (1978-2002):** The Mazda RX-7 was the most popular car to use the Wankel rotary engine. It was a sports car that was produced in several generations.
* **Mazda RX-8 (2003-2012):** The Mazda RX-8 was the last production car to use the Wankel rotary engine. It was a sports car that was produced in limited numbers.
### Conclusion
The Wankel rotary engine is a unique and fascinating type of internal combustion engine that has been used in a limited number of production vehicles over the years. It offers several advantages over traditional piston engines, including smoother operation, higher power output, and a more compact size. However, it also has some disadvantages, including lower fuel efficiency, higher emissions, and reliability issues. As a result, the Wankel rotary engine has never been as popular as the traditional piston engine.
