The Mazda rotary / Wankel engine brings back memories to me of a personal nature. My dad worked as a research chemist for the likes of Shell and Esso/Exxon and when at Exxon Paramins division he was tasked with new engine oil formulations to help solve/overcome the rotor tip wear and sealing problems that the wankel engine suffered from. Also the higher thermal and localised temperatures the wankel engine would put components and lubrication under. On his home study desk he had a plastic desk toy of the wankel engine. Also were beautiful high colour and definition pictures of critical parts of the wankel engine. These pictures were before, during and after extensive bench an road testing with various different formulations. Wanting to be an engineer myself I had an early insight into how detailed, complex and expensive solving engineering problems can be.
Also why no oils are the same and why one should use only manufacturer recommend fluids *especially* on new technology engines. e.g. Wankel and MultiAir. The research chemists/additives specialist work hand in hand with the manufacturers to formulate new oils to solve current challenges.
https://www.sae.org/publications/technical-papers/content/730047/
Of course after time and down the line the various technical specifications and requirements are standardised into "industry" standards and all oil manufacturers then level up to the same and one as a consumer has more choice.
Also why no oils are the same and why one should use only manufacturer recommend fluids *especially* on new technology engines. e.g. Wankel and MultiAir. The research chemists/additives specialist work hand in hand with the manufacturers to formulate new oils to solve current challenges.
https://www.sae.org/publications/technical-papers/content/730047/
Of course after time and down the line the various technical specifications and requirements are standardised into "industry" standards and all oil manufacturers then level up to the same and one as a consumer has more choice.