Answer:
An engine designed by Felix Wankel and idea bought/funded by Mazda to use in vehicles. Normally was to be used in aircrafts due to its lightweight and great power to weight ratios. These engines are very different from piston, creating the combustion process all in one chamber. Rotary engines are known to be lemons because if you are not a car enthusiast, then you don't know much about how to take care of a rotary engine car. I am not saying it is unreliable but it is unforgiving to abuse and mistreatment than other cars. If you take care of your car very well, then you can own a rotary, along with the right knowledge.