After 45 years of production, auto brand Mazda has officially stopped producing its famous rotary engine. Recently, the brand announced that production for its Renesis engine, the only existing rotary engine currently, would end. The rotary engine is known for its performance, but it's also known for being rather inefficient in terms of fuel usage and having a large amount of carbon emissions. The rotary engines will be switched for the brand's latest SkyActiv technologies.