I recently start fueling the gas with V-Power from Shell, all I can say is, I really can notice a different from acceleration, however, ever since I have my car, I've always leave my ESP on, never turned off, so my question is, since the system is designed to increase the "grip" and stability during accelerating, so will it seriously affect the power output, and even the gas mileage!!!

 

The ESP should only work on slippery surfaces. It prevents over and under steer.
The traction control applies brakes and backs off the gas to keep the wheels from
spinning.