Liberty 3.7L spark plugs


Getting ready to change out the spark plugs on my 2006 Liberty 3.7L w/auto tranny & have a question about which type is the best.

ALSO....would like to know if anyone can tell me what the spark plug oem information is on the data sticker under the hood. The rubber hood seal rides right on top of the line where it give the spark plug info & on mine its all rubbed away by wear.

the available types are :

a) copper
b) platinum
c) double platinum
d) iridium

and they go up in price with each type. I usually use the standard copper but this time I'm inclined to try the iridium ones & would like to know if anyone has used them before with a positive experience. They're touted to give a more complete burn of the air/fuel mixture with a better idle along with improved performance AND mileage....��

My Liberty engine is starting to lack performance in an inclined roadway but otherwise it runs like a top, starts right up & idles pretty good with a slight amount of roughness so if it ain't broke, don't fix it...spark plug wise has been my approach.

Many Youtube spark plug aficionados really promote the iridium plugs so are they really as good as they're touted to be?
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NGK (6987) ZFR6F-11G V-Power Spark Plug are original OEM

Iridium are more expensive and require a but more energy to spark than copper, single or double platinum.
And given todays coil on plug engines this is not an issue. Older distributer engine may suffer with iridium. MAY
Iridium will outlast them all. They come gapped properly and are prone to break if you try to increase the gap. Actually, all plugs come gapped properly anymore.
For a tune up change air filter. Clean the TB and IAC. Clean battery terminals and the other ends of the grounds.
When changing plugs make sure the engine is cold. Turn them in by hand to endure you catch the threads and seat to the correct torque. Over-tight strips and under-tight will cause missing.

Never look down on anyone unless you are helping them up - Jesse Jackson