A gallon of gasoline contains about 154,000 BTUs. That doesn’t change. What does change is the efficiency with which those BTUs are extracted.
Modern engines extract about 80 percent of the BTUs in the fuel. The Fuel Ox™ increases efficiency by lowering the residence time (see above). It also improves efficiency by aiding the catalyst process and unclogging injectors, making it easier for engines to burn fuel and indirectly increasing mileage or hours of operation.
The short answer is that nothing increases BTU’s. However The Fuel Ox™ helps engines extract the quantity of BTUs in the fuel more efficiently.