At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2
In summary it finds that there is a "sweet spot" that can be achieved with controlled introduction of Hydrogen at the intake manifold by using a mixer before it enters the combustion chamber. As a result diesel consumption can be reduced. Read the whole thing. It is and independent study.