I have had my HFA for about 4 months. I have a 2002 VW Jetta, that was beginning to be sluggish with lost power, and noticeable engine noise even with good maintenance. Well my car now runs smoothly, little or no engine noise, and has the power of much newer car. I also had 2 close calls that should have been an accident and somehow the other drivers avoided a collision with me. Awesome product

Linda Aydt February 23, 2017