ABSOLUTELY. As far as I have learned so far, DIESELS LOVE HYDROGEN. All our diesel test cars, pickup trucks, 18-wheelers (12.7 liter turbo diesels) and large stationary generators (19 liter turbo diesel) in California, Nevada, Tennessee, Israel, Italy and more, gained anywhere from 11% to 77% better fuel economy. Diesel installation is much simpler, even if you have a Turbo Charger and an Inter-Cooler, and the results are indicating an oncoming diesel revolution!
For a regular diesel, connect the Hydrogen hose between the air filter and the intake manifold.
Diesels converted to use VEGGIE OIL or BIO DIESEL will enjoy from Water4Gas technology as well. I am now testing a standard non-converted Volkswagen Jetta TDI (turbo diesel injection). It already achieved over 60 MPG with Water4Gas only, and next I'm going to test Hydrogen-on-demand together with UNHEATED VEGGIE OIL, my fuel heater, diesel-specific fuel additives, etc., trying to achieve 80 MPG and beyond.
The nice aspect about diesels is how EASY it is to gain more mileage. My understanding is this: since there is no computerized timing control on most diesels, the fast-ignited Hydrogen will not have to "argue" with a stupid computer, but will rather ignite at a better timing. This is not true to all new models, but is true for most trucks running on the road today.
In my humble opinion, diesel is the way to go!