I've had the 5 Star custom tune on my 2011 5.0L for about 4 months now and love it. I still have the stock air filter and exhaust but the tune alone made a noticeable difference. It's an 87 octane tune, I think the best part is the shift firmness. Really notice it in the upper rpm's. I did have to adjust the shift point in 1st gear as it was red lining at times when I put her to the floor. Well worth the money IMO.