You're meant to fill your car with it!
After my initial mocking, im consistently getting 1.5-2 MPG average higher than my usual Momentum99 fill-ups (on 3 full fill-ups)
Obviously not scientific but I do 450-500 miles per week, and my normal drive I used to average 25-26 MPG, with vpower i'm getting 27-28 MPG. Even if im subconsciously driving differently I'll take it