# Spark plug recommendations



## pL2014 (Dec 29, 2013)

The '14s appear to be a lot less finicky. I've never had the hesitation and things that other with earlier model years have dealt with. They also seem to handle 87 octane better. I just run the factory plugs but I did check the gap and they were off.


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## cruze01 (Mar 25, 2011)

I changed the plugs in my 2013 1.4 last week. 58,000 miles on the original Iridium's, the car was still running good. All 4 had eroded out to about .034 and #3 was completely loose (I don't know how it was holding compression), I'm glad I went ahead a done it. Looks like 60K is the limit on these.Overall I have no complaints, I went back with the AC DELCO Iridium.


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## Jontes (Feb 14, 2015)

I have some hesitation, rough idle etc, and I'm wondering if it's my spark plugs, or maybe I should regap them, maybe I'm better off with the factory plugs or if im Better off with plugs that are better than factory...idk


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## obermd (Mar 3, 2012)

cruze01 said:


> I changed the plugs in my 2013 1.4 last week. 58,000 miles on the original Iridium's, the car was still running good. All 4 had eroded out to about .034 and #3 was completely loose (I don't know how it was holding compression), I'm glad I went ahead a done it. Looks like 60K is the limit on these.Overall I have no complaints, I went back with the AC DELCO Iridium.
> View attachment 181217


The 2013s and later recommend a spark plug change at 60K miles. The 2011 and 2012 had this at 100K miles.


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## Jontes (Feb 14, 2015)

What's the recommended gap for plugs ? In the '14?


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## Jontes (Feb 14, 2015)

obermd said:


> cruze01 said:
> 
> 
> > I changed the plugs in my 2013 1.4 last week. 58,000 miles on the original Iridium's, the car was still running good. All 4 had eroded out to about .034 and #3 was completely loose (I don't know how it was holding compression), I'm glad I went ahead a done it. Looks like 60K is the limit on these.Overall I have no complaints, I went back with the AC DELCO Iridium.
> ...


Even when it's time to change mine, which plugs should I go with?


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## obermd (Mar 3, 2012)

You have three choices -

OEM plugs - NGK IFR series plugs rebranded by AC Delco
NGK BKR7EX vPower - copper, 15-20K miles before replacement
NGK BKR8EIX - Iridium, 45K? before replacement. 

The BKR series plugs I listed have noticeable improvements at lower RPMs but have a shorter lifespan than the OEM plugs. The NGK BKR8EIX plugs are rated for 60K miles but running them at lower RPMs erodes the electrodes quicker.


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## Jontes (Feb 14, 2015)

obermd said:


> You have three choices -
> 
> OEM plugs - NGK IFR series plugs rebranded by AC Delco
> NGK BKR7EX vPower - copper, 15-20K miles before replacement
> ...


And which ever one I choose I should just stick with the gap space that's in the manual?

.028"?


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## obermd (Mar 3, 2012)

Jontes said:


> And which ever one I choose I should just stick with the gap space that's in the manual?
> 
> .028"?


Yes. Take a look at http://www.cruzetalk.com/forum/34-1-4l-turbo/46833-new-copper-spark-plugs.html for my analysis of plug gap and gap growth.


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## Jontes (Feb 14, 2015)

obermd said:


> Jontes said:
> 
> 
> > And which ever one I choose I should just stick with the gap space that's in the manual?
> ...


Thanks for your help I'm gonna pick up a set of NGK V-Power BKR7E's n test them out still gonna keep my stock, I'm sitting about 33k miles, gonna check the gaps on them as well


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## pL2014 (Dec 29, 2013)

Jontes said:


> Thanks for your help I'm gonna pick up a set of NGK V-Power BKR7E's n test them out still gonna keep my stock, I'm sitting about 33k miles, gonna check the gaps on them as well


I've got similar mileage on my '14 (~31k). I gapped mine to 0.028 at about 5000 miles. Mine from the factory were anywhere between 0.022 and 0.030 if memory serves.


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## NickD (Dec 10, 2011)

Ha, I can remember when AC Delco manufactured spark plugs, try the lowest bidder today.

Been running my Cruze at a 25 mil gap (mil = 0.001 inches), but does take a bit of reforming as the ground electrode has to be perpendicular to the center electrode. This takes some skill. I still clean my plugs about every 15K miles, still burning carbon, use a ground walnut shell blaster. I can tell the difference.

Misfires are catastrophic to the catalytic converter plus reduce both performance and fuel economy, and cleaning the plugs on the Cruze is an absolute pleasure compared to many other vehicles.

Ha, while Tesla was zapping stuff, Kettering was doing the same thing with a much smaller spark, he's the guy that started Delco, but GM ate him up. Way ahead of Henry Ford in point gap ignition systems still using a magneto type vibrator system with extremely short life. But when the patents expired, Henry jumped to the Kettering System used in the Model A Ford. 

Ha, a set of points generates a much hotter spark than any solid state ignition system all based on di/dt, not a transistor can switch off that fast. But are far more reliable at the cost of reducing the potential energy. A capacitive discharge ignition system would be far superior, but also have to deal with the bean counters. Just replace those points as cheap as possible.

Ha, the electronics behind this spark are far cheaper than any distributor that requires casting and machining, but you won't find this when you try to buy a replacement. Just bend over and smile.


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## NickD (Dec 10, 2011)

Always disagreements on this subject, be there are not very many board members with over 35 years of experience in designing and testing ignition systems.

Still happy with Autolite APP3923 double platinum plugs, clean them at 15K and 30K miles, and dump them at 45K miles. Have the mass to carry away that heat.

But still looking for something better. Had way too many blowby problems with NGK's, and needle point center electrodes is nothing short of being completely stupid. 

Always check the resistance of your plugs between the connecting and center electrodes. that carbon element can burn up, should read about 8,000 ohms. Could have another unexpected gap. Course those crazy conductive springs tend to get hung up inside the shoulders of the boots. That really produces a heck of a large gap,


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