Marvel Mystery Oil is NOT nor ever was approved for use in aircraft fuel or oil. It is, however, commonly used...
Marvel Mystery Oil is composed primarily mineral spirits (Stottard Solvent). Why one would but a solvent in their lubricating oil has always mystified me. Maybe that's the Mystery in Mystery Oil... The general consensus is it does no harm in the recommended concentration when used in the fuel, but it does reduce the octane rating, so too much could cause trouble. How adding a solvent to the fuel prevents lead deposits from developing or valves from sticking is also a mystery... TCP is a lead scavenger. It combines chemically with the lead, preventing the lead from forming compounds that will stick to the engine guts, and allows the lead instead to be carried out the exhaust with the rest of the combustion gasses. Alcor TCP is approved for use in aircraft fuel systems. Leaded fuels generally contain bromide compounds to aid in scavenging the lead (as lead bromide) but the combustion temperatures achieved in our low compression engines are often not sufficient to complete the act. John Cooper Skyport Services www.skyportservices.net
