Everyone wants more power and better mileage, probably the latter more than the former. When Mix-I-Go was originally made in 1927, Robert Bell made a multi-function formula out of his original detergent for the Model-T combined with new technology to mix water and fuel.
Everyone claims to "improve combustion", but how does that work? After all, you can't make gasoline burn with more energy than its chemical maximum, because car engines are not atomic reactors. But you can create an environment in the engine that makes a greater percentage of the maximum energy from combustion be translated into work and mileage. And that's what Mix-I-Go has always done. Its combustion improver "slows the burn" of gasoline (at least that's how they used to say it in the 50s and 60s) by preventing pre-oxidation reactions from happening immediately after the gasoline or ethanol is sprayed into the cylinder and before the sparkplug ignites it. When you combine this effect with the effects of the detergents and other ingredients, Mix-I-Go users see consistent gains in their fuel mileage and they get better horsepower gains in their engines.
Now, we're not talking about a "guaranteed 25% gas mileage improvement" - that's a red flag for snake oil there. But 5-12% is quite reasonable to see. Mix-I-Go hasn't been around since 1927 by not delivering on its promises.
Check out more products designed to improve fuel economy.