The best-quality programmer for 5.3 Silverado will look after fuel economy and make sure you increase miles per gallon. When the power and torque are increased by the programmer, there’s fuel economy as a result.
The tuner increases the timing of the fuel delivery, resulting in a more complete burn. Thus, you get more power out of your fuel than you would have done otherwise.
Another way mileage improves is when you boost your horsepower and run your vehicle on high gear. As there is less downshift involved, running on a higher gear decreases fuel consumption.