Best and worst spark plugs and why.

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Fort Drum N.Y
I have always heard NGK has good spark plugs. Do they make any that aren't so great? I have also heard bosch plugs are the worst. Why? Do they burn out prematurely? What about other brands like auto lite and e3? ( side note: recently bought NGK G-Power a 4 pack for 12 bucks on amazon. Anyone use these?)
 
I kinda run what the vehicle came with from the factory.

If I did not go with factory plugs, then NGK would be my pick. Based on reputation and visual quality.

I am not into gimmicky plugs that claim more power or have multiple electrodes, etc.
 
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I agree to run what came in the vehicle from the factory. I also agree that NGK (or Denso) would be my
substitute if OE weren't available. I have had good luck running Autolite Iridiums in a couple
of Fords that called for Motorcraft plugs....
 
I would say it's very much vehicle dependent. For example copper Champions run great in my CJ-7 but I would not run them in my Mercedes, nor would I use Bosch in the Jeep.
 
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Originally Posted by Egg_Head
I would say it's very much vehicle dependent. For example copper Champions run great in my CJ-7 but I would not run them in my Mercedes, nor would I use Bosch in the Jeep.






Why though?
 
I think a lot of it has to do with the ignition system that the car has in it. Years, years ago I had a '94 LeSabre that I installed BOSCH +4 plugs in. I was a young kid and thought I was doing Good to an old relic putting some fancy German plugs in.

Car ran like garbage after a few weeks. Put new Regular ACDelco plugs in it and it ran great again. In doing some research, I came to the conclusion that the LeSabre of said vintage had an ignition system where it fires a waste spark opposite of the ignition. So essence the plugs were doing double duty.

Perhaps manufacturers of plugs, in particular applications, account for these set-forth endurance requirements.

As far as I have always known, NGK makes ACDelco and Autolite makes Motorcraft. As a universal plug, I have always used NGK in everything with no drama. Many of my Honda's have come OE with Denso. I have replaced factory Denso in Hondas with Denso again and with NGK and both performed just as good.
 
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Also keep in mind, the market for counterfeit spark plugs is a thing. If you sometimes see a deal too good to be true on NGK plugs, it could potentially be counterfeit.
 
I have always felt that the NGK plugs I get seem to have better quality control in the manufacturing. The threads are smoother and the gaps are more consistent, the finish even looks better. I like using them in my OPE and motorcycles but as far as my car and truck goes unless there is some major overriding issue I stick with what the factory installed. It is difficult to know what even small differences in Resistance, impedance, or heat will make to modern computer controlled ignition system. What bothers me the most is when I look at cross reference guides and see so many numbers from the same maker crossing to so many others. If they are all the same why make so many numbers.
 
Factory plug in most cases.
In my Oldsey and Corvette I use Autolite cheapie copper plugs.

In the '80s I put a set of plugs in a Chrysler LeBaron for a co-worker. Probably used Autolites; Champion was the factory plug.
I hate Champions...
Wouldn't run right...
She took it back to the dealer; they installed Champions and all was good.
Blew my mind.
 
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Seems crazy to me that plugs could make so much of a difference. It would seem like as long as the gap is correct it should work the same.
 
Originally Posted by Micahmcmeen
Originally Posted by Egg_Head
I would say it's very much vehicle dependent. For example copper Champions run great in my CJ-7 but I would not run them in my Mercedes, nor would I use Bosch in the Jeep.






Why though?

Different engine designs have different needs.
Simple as that.
 
Originally Posted by Micahmcmeen
I have always heard NGK has good spark plugs. Do they make any that aren't so great? I have also heard bosch plugs are the worst. Why? Do they burn out prematurely? What about other brands like auto lite and e3? ( side note: recently bought NGK G-Power a 4 pack for 12 bucks on amazon. Anyone use these?)

Best: one your vehicle's engine was speced to use.
Worst: random plug bought because it seemed better on paper or a magazine promised 0.2mpg more with it.
 
Years ago I had put Autolite Double Plats in our 05 T&C 3.8. Two years ago, I was gonna change them again. Grabbed some more Autolites at NAPA and looked at a couple of them before I paid....the threads looked downright rough. Never seen anything quite like it. Went with Champions instead.

When I pulled out the old Autolites, either 2 or 3 (can't remember for sure) of the 6 had the platinum pad missing from the ground electrode. When I saw that, I was really glad I had bought the Champions.
 
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