Unlikely to be 25HP, though
The standard Universal engine on the Cat30 was the Universal 25 (which has 21HP) or the 25XP which has 23 HP. Don't know why Universal used this confusing numbering (the Universal 30 has 25HP and the Universal 35 has 30HP).Anyway, I am sure consumption is as Stu says - my experience with the 25XP is an average of around 0.35 GPH, but that includes all usage, including idling. Very frugal engine.