Hello. I also have a unlimited supply of used hydraulic oil. I have centrafuged 60 gallons so far. You said you added 10% rug to your used hydraulic oil, do you also heat it before it gets injected to motor? Is the viscosity the same after you add rug to oil? ThxI just finished fuging a batch of hydraulic oil, I ended up mixing in about 10% gasoline and it looks great so far. I'll run it this weekend on a 550 mile road trip, we'll see how she does.