Mazda punches way above their weight when it comes to "moonshot" innovation over and over again. Few of them really "succeed" commercially (Rotary engine, miller-cycle engine, HCCI) but I respect them for constantly pushing the technology forward.

* https://en.wikipedia.org/wiki/Mazda_Wankel_engine

* https://en.wikipedia.org/wiki/Miller_cycle

* https://en.wikipedia.org/wiki/Skyactiv#Skyactiv-X

* https://en.wikipedia.org/wiki/Homogeneous_charge_compression...