The treatment ratio is the ratio of FFX to fuel. The higher the treatment ratio, the more fuel you need to use. The treatment ratio for FFX is between 1:5,000 and 1:10,000. This means that for every 5,000 or 10,000 parts of fuel you use, you will need one part of FFX.
Heavy fuels will have a lower treat ratio than No. 2 diesel, ethanol, or 83-89 octane fuels because they have a lower octane rating. The higher the octane number, the more energy it takes to ignite the fuel. This is why high-octane fuels are used in high-performance engines.