From what I gathered reading the analysis conclusion paper, both products are solvent based and SEEM similar. My understanding is that LC is used to keep oxidation in check, clean/soften deposits, and provide lubricity while FP cleans/softens fuel side deposits and provides additional fuel energy. I'm sure that the LC and FP obviously have different make-ups to tailor for each of their specific applications otherwise they could just sell the same product for both. Will LC in the fuel cause problems? Doubt it for a one shot mistaken application since it is safe on seals and such. But I'm no expert. Have you posted this on the Lube Control forum yet?