Wow as I have some good exciting news about these spark plugs. I installed them in my 97 Ford F-150 4.6 V8 right along with some new Duralast Spark Plug Wires right, when I turn the ignition over to reveal the results, I was excited at the results of hearing the smooth idle of my ride with them new plugs and wires. I am impressed with the performance of those plugs. They improve my engine performance. They are top notch. I definitely recommend them to anyone. I put my trust in them. They stopped the low speed hesitation i was experiencing, now I do not hear or feel it anymore. Truck feels better. Great investment in them, Autolite you're the best. I had a misfiring on cylinder 3. I am back on the road, they exceed performance to me, I give them a A+++++ beyond. My truck drive very smooth now, better than before. I do not feel like I can feel the idle at a stop light or stop sign, man I got some excellent plugs, now time will tell how good they will last from now until 5 years of the warranty. I'm ready to see will they improve great gas mileage.

The plugs all had smudges and grease on them out of the box, could tell they were cleaned and the boxes were opened before I purchased them.