Review on Spectra Premium C 551 Coil Plug by Kevin Folsom

Let me start by saying that I only installed them for a day. My Matrix is 11 years old and seems to be a bit lethargic lately. I changed the spark plugs and it helped a few. I've gotten the occasional misfire fault (even with good spark plugs) so considering the cost of these coils I thought it was worth a try. The car became a bit more responsive after installing the coils, allowing them to achieve the goal I had in mind. I was a little apprehensive about these reels as they were a lot cheaper than other brands but they seem to last (at least) as long as the original Denso reels. They are just as strong as the original coils and the spring seems to sit closer to the spark plugs and make better contact than the ones I've replaced, but I don't know if the spring makes better contact than any brand new coil (or new Densos kit as mine is over 11 years old). Can't comment on durability yet, but at least on day one they work better than the ones I replaced.