I think UCL is similar to the oil portion of FP60, (FP60 being oil and solvents). I think UCL is a straight oil, possibly with a cleaner but nobody knows. Not only would it not be a problem, but it might be good idea to mix a solvent cleaner once in a while with UCL. I personally would use one that was a high solvent for a lot of reasons. The main one being why run something that is mostly a lubricating oil to aid another lubricating oil. Also, if there is any buildup the high solvent will clean it out. I personally wouldn't alternate tanks, some people believe high solvents will mess with seals if used all the time, but I sure would run some Techron once every few months, and either pic between FP60 or Lucas for every tank, as they probably are pretty similar.
Techron flash point 100f, FP60 flash point 350, UCL flash point <400f. I bet Techron is more solvent than oil, and FP60 is more oil than solvent. Because UCL has a low flash point and no evaporation rate, I would think it's the one product that you could possibly overdose on, but I think it would probably take a lot to do it. FP is not far behind it either, but again since the main ingredient of the sum total of the gas tank is highly flamable, it probably is never going to be an issue. All the MSDS's are available, nothing suggests any of these additives can't be mixed.
