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I'm looking for the best spark plugs I could possibly put in my 2015 1LT Cruze w/1.4 Turbo DOHC engine. I have heard of the common engine hesitation and lower end grunt.

I've also seen a couple threads on copper plugs, but haven't seen much info as to the best plug which may last longer and provide the best performance at both high AND low RPM.

Open to ideas, really looking forward to everyone's advice!
 

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The gap and the temperature range for the plugs depends on whether you are running stock, a tune, or modified components like a larger turbo or "off-road" exhaust mods. Personally, I've had good success with the NGK FR7BHX-S Ruthenium plugs with a 0.028 gap (stock tune, no mods).
This thread explains a lot on plugs/plug gaps/etc.
 
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I felt the need to modify my response. :D

Those plugs with a ZZP coil pack. Some will say stay OEM, some say the MSD pack. I haven't tried them all, but I know the ZZP pack rocks. (y)
 

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The best plugs period are the NGK Ruthenium HX. They are literally made for turbo cars. I can confirm that both gas mileage and responsiveness increased with these plugs. My dad just did them in his 2017 Malibu 1.5T now and he actually got better gas mileage than he ever got.
I also got an MSD pack, but didn't do both at the same time.
 

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I've also seen a couple threads on copper plugs, but haven't seen much info as to the best plug which may last longer and provide the best performance at both high AND low end grunt.
Is the engine stock or modified (tune, mechanical modifications, ect)?

If it's stock, use the OEM plug, the best quality fuel available, and keep up religiously on your fuel/induction system maintenance. There isn't much you can do with a stock engine to make it better than GM did.

If the engine is modified that is a different story.
 

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Is the engine stock or modified (tune, mechanical modifications, ect)?

If it's stock, use the OEM plug, the best quality fuel available, and keep up religiously on your fuel/induction system maintenance. There isn't much you can do with a stock engine to make it better than GM did.

If the engine is modified that is a different story.
There are always ways to improve from the factory, since factories need to meet price points. This means that using things like cheap copper plugs saves money and generates a source of revenue for the dealership. The other thing is that iridium plugs were not that great for high boost applications in the past, since the engine was originally designed in the 2000s; copper plugs were often used for turbo applications due to fouling and the lack of reliability of iridum. Now that there is Ruthenium HX built specifically for turbo applications; that is no longer a problem. I ran copper in turbo cars until recently for this reason. However Ruthenium is legit and definitely an upgrade over stock.
 

· The Nuclear Option
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There are always ways to improve from the factory, since factories need to meet price points. This means that using things like cheap copper plugs saves money and generates a source of revenue for the dealership.
Copper spark plugs from the factory? :LOL: I can believe we're only 2 1/2 months away from 1993. Sorry, but that made me laugh. I'm not aware of any modern automotive engine that uses cheap copper spark plugs from the factory.

The other thing is that iridium plugs were not that great for high boost applications in the past, since the engine was originally designed in the 2000s; copper plugs were often used for turbo applications due to fouling and the lack of reliability of iridum.
I agree. I use non-resistor "copper" spark plugs. But the OP was asking about "longevity and more low end grunt" which a "copper" plug will not achieve better longevity.

Now that there is Ruthenium HX built specifically for turbo applications; that is no longer a problem. I ran copper in turbo cars until recently for this reason. However Ruthenium is legit and definitely an upgrade over stock.
I tried them and I couldn't see a difference. But your results may vary.
 

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I did notice a difference, I did them right after buying the car... about 250 miles after actually. Not sure if the plugs in my car had been changed before, but they didn't look too bad and my car had 84k miles.
I'm sure there are still cars that come with copper plugs from the factory, just like how Hyundai doesn't have immobilizers or even ignition locks on their lower end cars despite everyone else having them for decades now lol.

As far as "low end grunt" I don't think there are any plugs that will specifically deliver that.... Ruthenium HX is supposed to "help" with ignition in this sense but it doesn't exactly give you low end "grunt" especially not on an engine like this. The biggest change for me that gave me "low end grunt" was switching from regular gas to E15 / 88 Octane.
 
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