Generator shown below is open skid mounted but our units are enclosed in a weather resistant cabinet and are mounted on trailers with an auxiliary fuel tank.
This unit has a 190 gallon tank and at full load this unit uses approximately 12.7 gallon per hour. With a full tank you should get approximately 15 hours of run time. Of course most of the time you are not running at full load and it is possible you could get a much longer run time.