What would be nice is to be able to generate enough hydrogen to fuel a motor without gasoline !
Stanley Myers was suppose to have made a VW buggy run with no gasoline just hydrogen .
Octane rating is 130 , Quote from Wikipedia : Hydrogen does not fit well into the normal definitions of octane number. It has a very high RON and a low MON , so that it has low knock resistance in practice , due to its low ignition energy (primarily due to its low dissociation energy) and extremely high flame speed. These traits are highly desirable in rocket engines, but undesirable in Otto-cycle engines. However, as a minor blending component (e.g. in a bi-fuel vehicle), hydrogen raises overall knock resistance. Flame speed is limited by the rest of the component species; hydrogen may reduce knock by contributing its high thermal conductivity .

Gil