A Wankel engine has stronger flows of air-fuel mixture and a longer operating cycle than a reciprocating piston engine, achieving a thorough mixing of hydrogen and air. The result is a homogeneous mixture with no hot spots in the engine, which is crucial for hydrogen combustion. Hydrogen/air fuel mixtures are quicker to ignite than gasoline mixtures with a high burning rate, resulting in all the fuel being burnt with no unburnt fuel being ejected into the exhaust stream as is the case using gasoline fuel in rotary engines. Emissions are near zero, even with oil lubrication of apex seals.