I am renting an Infinity crossover (small SUV) on my Atlanta business trip this next couple of days. It has an instantaneous fuel efficiency monitor with bar graph that changes in real time. The graph is graduated with 10mpg, 20mpg, 30mpg at the top. Stepping on the gas hard puts it in single digit instantaneous mpg. Drafting, coasting, and maintaing a given speed keeps it at 30mpg. The average, running mpg was aroung 16mpg.
So, the single best way to increase mpg is to drive the vehicle like there is a rotton egg behind the gas pedal and a tall cup of ink sitting on the dash. If your ST was equipped as such, stepping down hard on either the gas or the brake would have severe consequences.
People do jackrabbit stops. They keep on the gas only to have to hard brake. If you can always avoid both you can probably increase your mpg by at last 3 to 5 mpg, or more.
TJR