Spark Plugs E3.62 Premium Automotive Spark Plug with DiamondFIRE Technology, 14mm Thread Diameter, 0.708” Reach, Taper Seat, Resistor, Pack of 1

So I purchased a crate motor 2 years ago from jugs automotive when I purchase the engine I purchased AC Delco iridium spark plugs from Amazon after engine installation and spark plug installation I developed a knocking and pinging noise I replaced the knock sensor and of course it already had the new plugs wires cap rotor and everything else under the hood I do know at the time where we get fuel changed the quality of gas for the winter I then started using premium fuel to stop the pinging at low rpm under load . Well well well . I went ahead and bought a set of E3 spark plugs oh my gosh throttle response amazing idle amazing no more pinging and the 5.7 runs amazing hard to believe the E3 changed the engine that much ! Some people say they have snake oil to sell you and e3's are a joke but I'm here to tell you they work phenomenal

Amazon sent me the wrong ones, I bought the right ones from a local brick and mortar. Amazon paid for the return and refunded my money. These are now the 3 set of these I have put in a car. This set went into a 3.1L 175hp Pontiac. Noticeable improvement in throttle response, and top end pull. BUT - don't expect to blown away. Combined with a Thrush baffled muffler, K&N drop in air filter, new OEM coils, and MSD 8.5mm plug wires, I probably netted +10% HP..... More impressive, my combined mileage has improved from 19.5mpg to 23.5mpg. Again, this is the combo of parts that achieved this, not the E3s alone.... For the mileage and meager performance increase, the full combo was well worth $300.... ***UPDATE*** 11.20.2020 I no longer own this car, but felt the need to update with other findings. Not all cars are happy with these. Most recently, a 2004 Grand Cherokee with the non-HO 4.7, responded poorly with rough idle and a top end that just felt off - like peak power started to roll off earlier. They were removed and factory spec copper plugs put back in. My 70 'Cuda was not happy either (340 stroked to 408, MSD distributorless ignition 6LS, Holly Dominator EFI). She has quite a bit of cam and already idles a touch rough. After the E3's she didn't want to idle at all despite attempts to tune the 6LS and Dominator systems to compensate. She was just plain angry. Never even bothered with a test drive. Autolite Platinums were installed. A 2000 Grand Caravan 3.0 v6 also suffered a poor idle, and actually saw an almost 1mpg loss. Autolite Platinums were installed.

They work great and have a long life.

I'll tell you 98% of the negative reviews, the people broke the ceramic in the plug installing them. It happens all the time. The plugs have shown improvements in HP on a Dyno and have shown better mpg on some cars. As with anything else it is personal preference. simply put they will give a little plus in performance and mileage. Most people can't tell the difference because day to day drive varies. In racing even the smallest + in performance will be used. Every 10th of a second can make the difference between winning and losing. To the average Joe driving to work a few miles a day will not even notice and will more then likely say they didn't help. From what I seen is they put their foot in the gas more looking for more and end up using more gas.

Noticeable performance increase!

I've been using these for awhile now in several different applications and work great

Was running Bosch platinums but decided to give these a try. Noticed a difference as soon as I started the motor. More power and smoother running. Gas mileage is up at least 2-3 miles per gallon. Will definitely be sticking with these from now on.

My Original review is below, Please read the update at the bottom, These plugs destroyed my vehicle. These are spark plugs, They all preform the same basic function with little deviation between brands unless you are running a high-performance vehicle with some insanely low tuning tolerances. I have to think that most of the negative reviews are due to installation error or other personal vehicle problems. These plugs go in easily and don't require any gapping - Even the "pre-gapped" plugs need checking! I put them in my 2008 Ford Crown Vic LX, No problems. I can't comment on mileage or fuel efficiency since I haven't run them very long. The engine does sound smoother when accelerating quickly though. My only complaint is that I ordered 8 of these (For a V8 of course), They came in a cardboard envelope that had 8 individual spark plug packages in it, Some of the spark plugs had come out of those packages and were loose in there. I don't know why they couldn't have used a little tape, Or wrapped the plugs up in sets of 4. None of the plugs seemed damaged, But the potential was definitely there. ***UPDATE*** Well, After installing these plugs, I began having engine trouble. Long story short several pieces of the "3 conductive tips" on the end came off of TWO different plugs and ruined the cylinders and piston rings. Don't know how. Poor quality control? These are fakes? Heat? Took it to a shop, Sure enough, They found pieces of these jammed in the cylinders. I sold the car for scrap value, Wasn't worth fixing since a new motor was more than the vehicle was worth. That's exactly what the guy I sold it to had to do. Replace the whole engine. Buyer beware, I have since just stuck to traditional brands and bought them at autoparts stores to be 100% sure they are genuine.