There are arguments about as to whether this does anything or not. Personally, I have not seen enough gains to justify spending the extra money. My stock ignition coil was cracked and not functioning right at 40,000 miles so I had replaced it with the MSD coil only because I got it cheap. I bought it and a set of Ford Racing wires for only $50 because the company I know was clearing out their inventory. I figured what the Hell, at that cheap, what is the most that I could lose. I have driven with it for about 35,000 miles and didn't really notice anything super about it. But then again, that's just my judgement call.