E3.70 Premium Automotive Spark Plug with DiamondFIRE Technology - High Performance Spark Plug for Cars, Trucks & SUVs - Improves Fuel Efficiency & Engine Power - Ideal for Daily Driving, Off-Road & Racing (Pack of 1)

They work have not seen any of the clams they have made but they work I got them because I don't like Champion and everything I read on the Champion plugs people had problems with them not firing same for me with Champion plugs but wanted to try the one piece design. I would recommend the Kroil for remove of old plugs I did a my truck and sisters car turn the plugs 1/8 to 1/4 turn spray in Kroil wait 15 to 20 minutes and they all came out didn't brake one off 16 plugs not one even had trouble coming out.I received these plugs and was excited! I ordered them last year end of May 2012. I installed them near the end Jul 2013. When installing I realized I had one bent plug(serves me right for not checking the packages before storing). It would have cost me more to send back with the shipping and everything then to buy a new one(so I did order a new one). However, the plugs work AWESOME (yeeaaahh(say it like lil john))! In the end I just order a new one from Amazon.com.Awesome.Really like these plugs, they are a one piece unit that will not break off into the heads on these 5.4L Triton engines. We replaced the factory plugs with these and a set of Bravex coil packs, and the truck runs so much better now. I would recommend these plugs to anyone over the pricy Autolite, Champion, or Motorcraft.These are a good replacement for the two price plugs for the Ford's and they fire better than a standard replacementI don't know should this one star should be for Amazon or E3sparkplugs??Amazon fit engine showed they would fit my 2012 ford expedition (5.4L). I bought them, They don't fit.Amazon should modify their fit engine on their website with sensitive equipment to determine the fitness of certain stuff on certain model.I should have contacted E3 spark plugs technical support before making the purchase. I don't know how to ship them back, they will cost me almost double the price.Update;Thanks Amazon for refunding me. I would give it 5 stars, amazon was so cooperative.Worked great on my 2005 F-150 fx4 5.4L. Better throttle response, smoother idling and quicker start ups. Now i don't have to about breaking plugs with the stronger design over stock. When i got my truck someone had already changed the motorcraft plugs to autolite plugs. But my truck felt sluggish like it was stopped up or now getting a good burn. So sea foamed the motor than put in the E3 plugs and was amazed with the more power i got. Plus the E3 have a 100,000 mile guarantee.I got a set of E3 plugs for my 2006 Ford F-150 5.4 and have no complaints on the product, my fuel mileage got better and the performance is like a new truck. So I suggest other customers give them a try, you wont be disappointed.