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Discussion Starter · #1 ·
I have been going through all the spark plug threads and I am confused from all the info to say the least. What I am looking for is what plugs to get and what to gap them at? I am going on a long road trip in March and want to get some pretty good MPG while improving the power some. Just looking for tried and true info.
Was looking at the Denso Iridium Power #IK22 that are supposed to be pre-gaped at 0.032.

2011 LT 1.4 Turbo
Auto
55K Miles on it
Will Have the Injein Cold Air Intake on next month
Lowered with spring kit
18" wheels
No Tune
 

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I'd stick with the NGK line of plugs. NGK BKR7E vPower Copper for the best low end performance or the NGK BKR8EIX Iridium for longer life plugs that are almost as good at low RPMs. Since you have an automatic I'm not sure you'll benefit from the vPower's lower RPM range abilities.

As for improving your fuel economy, boost your tire PSI to sidewall pressure and slow down. No spark plug I've seen has made a noticeable difference on fuel economy.
 

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Discussion Starter · #3 · (Edited)
My PSI is set at 40 psi right now but with the weather right now it jumps around. I was going to re-gap the plugs but just figured I would throw some new ones in. Was thinking of gaping them at .32 or .34. Since I seen it helps with the MPG.
Going to have new tires and oil changed before I leave. Thinking of adding MOA when I change the oil. I am stuck between using Royal Purple or Valvoline right now. To many choices lol
 

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I've seen above-rated mileage on mine with Valvoline full syn. and 40-44 PSI in the factory Firestone FR710's. I don't need any possible extra performance from wider plug gap bad enough to warrant pulling my plugs every 10-15,000? miles to check the gap, risk boogering up the threads in the aluminum head, problems caused by misfire, etc.
 

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Hey everyone Im new to the forum. I purchased and replaced my four spark plugs along with a engine coil the dealer said was cracked. The spark plugs come pregapped at .28. My car runs normal but i noticed I do not have any boost. I have lost torque and only get it in high rpms when im pushing it. I believe its due to the smaller gap. Does anyone have any knowledge on this? I want to re gap them but im scared of taking out the engine coil again as it seems its common for people to crack the engine coil when removing it. Thanks everyone
 

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Hey everyone Im new to the forum. I purchased and replaced my four spark plugs along with a engine coil the dealer said was cracked. The spark plugs come pregapped at .28. My car runs normal but i noticed I do not have any boost. I have lost torque and only get it in high rpms when im pushing it. I believe its due to the smaller gap. Does anyone have any knowledge on this? I want to re gap them but im scared of taking out the engine coil again as it seems its common for people to crack the engine coil when removing it. Thanks everyone
So what are the plugs did you put in? What octane are you running in it?

Don't tear the coil pack out - pry up gently at the end where the wires attach, then wiggle it until it comes loose. I've taken mine out many times and have yet to crack a boot.
 

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So what are the plugs did you put in? What octane are you running in it?

Don't tear the coil pack out - pry up gently at the end where the wires attach, then wiggle it until it comes loose. I've taken mine out many times and have yet to crack a boot.
im running 87 the lowest. and i cant remembe the plugs there pretty common ones that iv found on here. but there pregapped at .028. but yea im pretty sure thats the problem. I got back from work not too long ago im letting it cool down then im gonna gappen them to .035. i dont think ill tear or break the engine coil but if something does happen i have three boots from when i replaced the old one.
 

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im running 87 the lowest. and i cant remembe the plugs there pretty common ones that iv found on here. but there pregapped at .028. but yea im pretty sure thats the problem. I got back from work not too long ago im letting it cool down then im gonna gappen them to .035. i dont think ill tear or break the engine coil but if something does happen i have three boots from when i replaced the old one.
Well the 87 certainly isn't helping things. You can give it a shot, but seriously doubt it will make much of a difference. The car is pulling timing because it's knocking like crazy at low RPMs on low octane fuel. Turbo engines like higher octane gas with more knock resistance, especially in summer.
 

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im running 87 the lowest. and i cant remember the plugs there pretty common ones that iv found on here. but there pregapped at .028. but yea im pretty sure that's the problem. I got back from work not too long ago im letting it cool down then im gonna gappen them to .035. i dont think ill tear or break the engine coil but if something does happen i have three boots from when i replaced the old one.
Don't worry about messing up the coil pack as long as you are not "rough" with it. I don't think the plug gap is a problem. My plugs are set at .028 and I have no problems. As "j" said I think your problem is the gas you use. Try running a couple of tanks of premium and see what difference that makes. You may not think it is the same car it will respond differently, I guarantee it!!!
Every once in a while I think of running 89 octane but then am haunted by the lack of power my car has when running other than 93 octane.
 

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Don't worry about messing up the coil pack as long as you are not "rough" with it. I don't think the plug gap is a problem. My plugs are set at .028 and I have no problems. As "j" said I think your problem is the gas you use. Try running a couple of tanks of premium and see what difference that makes. You may not think it is the same car it will respond differently, I guarantee it!!!
Every once in a while I think of running 89 octane but then am haunted by the lack of power my car has when running other than 93 octane.
Ill deffinelty try it. but before i changed my engine coil and the spark plugs my car would pull significantly and now you can hardly feel any pull in lower rpms. but yea ill give it a shot.
 

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Ok Ive been doin alot of old school data logging with mpg, plug gapping, octane, and tire psi.
One thing I have definitely noticed is how there is NO gain what so ever with higher octane in a stock 1.4ltr whether or not you have an auto or man trans. Trust me on this, I live in TX speed limit is 75mph and there is tons of flat roads around to do equivalent testing. Our cars are stock tuned for 87 octane. Tire psi seems to do best at 33psi, I cant belive some of yall would go up to 40+psi I just guess yall like uneven tread wear. Spark plug gapping... I can talk about this all day, but Im not, Ill be breif. Our stock gapping is .026-.028, there is a -/+ tolerrance our ECM allows. If you have no tune, dont mess with the gap, leave it at .028 max. I have logged and recorded gaps ranging from .024 as a base all the way to .038 as the highest. With two differnt brands, Denso and NGK. If you want a good plug that wont be fouled or having to gap check every 10k-25k miles, go with the Denso, it has a stronger plug. Ngk is a great plug, but they have sadly dropped in quality that used to be the plugs to run. But anyways, if you dont have a tune psi at 33, leave your plugs gapped at .026-.028, and dont waste your money on higher octane fuel, that is just going to end up costing you in the long run. I might be retired, but Im still Goodwrench certified. Now once you have a tune, rock out with with .033 gap, 90+octane, and get some power goodies, then youll be good. Remember, our cars have an under power engine in a heavy car plus us and what ever else is in the car with you. GUYS please dont air your tires up to 40+psi thats a recipe for disaster. Oh crap forgot to add best MPG I got was 31 avg mpg. 33psi, .028 gap, 87oct, ac on full blast me my wife and three kids with a weeks load of luggage. 418mi trip one way. Avg speed was 70mph.
 

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Maybe you have one of the later years with the improved stock tune.
His YouTube channel indicates a 2011. I do wonder what he's looking for in his testing. MPG? Acceleration? It might be a different profile that doesn't bring the differences observed in driving. I know the car feels a lot different starting from a standing start as opposed to stomping on it while doing 25 MPH. Different enough that under the right conditions I think a Cruze at a standing start can pass a Cruze doing a rolling start.
 

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For me 87 will stall on take off if I'm not reving it "competitively" and wintertime will stall if Stabilitrak or Traction Control intervene
 

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My '14 LT2 is very much stock. Most of the time I run 87 Octane unless it gets hot out, and that's only if the daily temps will be >95 for more than about 2-3 days. When that happens I will run 91 Octane. The only difference is that the car is a bit more responsive to the throttle when it's hot and I'm running the 91 Octane than if it's hot out and I'm running 87. During cooler weather, I have noticed little to no difference which gas I run so I go with the 87.

My plugs are all gapped at 0.28 in and I've gone as wide as 0.32 in but aside from a little loss of low end power, comparatively speaking, I'm pretty happy with the gap at 0.28 in. Current plugs are 41-121 AC Delco.
 

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My '14 LT2 is very much stock. Most of the time I run 87 Octane unless it gets hot out, and that's only if the daily temps will be >95 for more than about 2-3 days. When that happens I will run 91 Octane. The only difference is that the car is a bit more responsive to the throttle when it's hot and I'm running the 91 Octane than if it's hot out and I'm running 87. During cooler weather, I have noticed little to no difference which gas I run so I go with the 87.

My plugs are all gapped at 0.28 in and I've gone as wide as 0.32 in but aside from a little loss of low end power, comparatively speaking, I'm pretty happy with the gap at 0.28 in. Current plugs are 41-121 AC Delco.
14 and up or ecu recalled pre 14 have different calibrations making the 87/91 a seamless transition.
 

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His YouTube channel indicates a 2011. I do wonder what he's looking for in his testing. MPG? Acceleration? It might be a different profile that doesn't bring the differences observed in driving. I know the car feels a lot different starting from a standing start as opposed to stomping on it while doing 25 MPH. Different enough that under the right conditions I think a Cruze at a standing start can pass a Cruze doing a rolling start.
Yes, my cruze is a 2011 LT 6spd auto. What I was looking at when I did 6mo of logging, I was looking for the best combination pretuned. The vid I have of my cruze, is my completed exhaust. It even states that in the discription. So like I said in my reply earlier, basicly stock tune, 87, .028 gap, and 33psi in the tires, is about the best your going to get for mpg. NOW, if you want increased performance, 93 oct with a strong octane bosster that isnt a cheap type, and up your gap to .030, and about the only thing your going to see is a little bit better acceleration. I honestly dont see how you can instantly see a differnce with out a tune, unless you have a 2014+ Cruze because the fuel signatures are differnt from the first run of the cruze. Yeah Im working with my guys at the shop to see whats going on with "stallish" and lack of power of the cruze to see if we can get it sumitted to GM for either a TSB or full out recall or just a trans recalibration.
 

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Yes, my cruze is a 2011 LT 6spd auto. What I was looking at when I did 6mo of logging, I was looking for the best combination pretuned. The vid I have of my cruze, is my completed exhaust. It even states that in the discription. So like I said in my reply earlier, basicly stock tune, 87, .028 gap, and 33psi in the tires, is about the best your going to get for mpg. NOW, if you want increased performance, 93 oct with a strong octane bosster that isnt a cheap type, and up your gap to .030, and about the only thing your going to see is a little bit better acceleration. I honestly dont see how you can instantly see a differnce with out a tune, unless you have a 2014+ Cruze because the fuel signatures are differnt from the first run of the cruze. Yeah Im working with my guys at the shop to see whats going on with "stallish" and lack of power of the cruze to see if we can get it sumitted to GM for either a TSB or full out recall or just a trans recalibration.
Another thing to take in to account is you can't just swing a 87 tank then a 93 tank and then a 89 tank. Car needs to be using a complete tank of 93 for a few tanks to get the trim to stick to 91. Kinda hard to explain but the fuel map is 91 when you fuel up and take off into traffic "responsibly". Did you do the ecu recall yet since you noted aut trans type? One more thing to look for is "KRD" in the glovebox.

 

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Yes, By Far the best Plugs that I Have tested for our Cruze's is the Denso IK22's... By far the most acceleration on hot summer 100 degree days... Ive tested most of the Ngk's Ixe8's ,Brb7 coppers, 120-21's 120-22's basicly all the a/c delcos and all the other Ngk.s,,, Nothing close to these Denso's.....Longevity remains to be seen...
 

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14 and up or ecu recalled pre 14 have different calibrations making the 87/91 a seamless transition.
I do still notice a difference between the 87 and 91 gas but when it's cooler out, the transition is almost unnoticeable. When it is hot out there really is a notable difference. If temps follow seasonal norms, I should be back to using 87 gas in about 6-8 weeks from now.
 
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