This chart estimates diesel fuel consumption for a generator based on the size of the generator and the load at which the generator is operating. Please note that this table is simply an estimate. Many other factors will affect the fuel efficiency of a diesel generator including design, fuel quality, air quality, and frequency of load changes.
Note that the table below does not account for smaller more residential units like the ones we sell. Our 5kW units that are very underrated by the U.S. Military would consume (assuming 65-100% load) roughly 0.42 gallons of diesel fuel per hour. Lower load would consume less and more load (i.e. pushing 100% continuously for an hour) would consumer more. The range at the low end would be around 0.25 gallons per hour and 0.60 gallons per hour at the high end.