# Spark gap moving target?



## Champagne Jam (Feb 3, 2016)

When I picked up my used Cruze, power was lacking. Fuel economy wasn't great either. So, like many in this forum, I checked the spark plug gap. 
Sure enough, the gaps were low. No problem, re-gaped and off to the races. Power was up as was economy. End of story? Nah.

I got the Tri tune and have loved it. Put in some new plugs and ran about 5k miles on it. So I checked the forum for gap info. You know, just to refresh my memory.
I see that .028 is the correct value, so I thought to myself. Hmm I think I did those at .030. So out they come.

Wait an darn minute. They are checking at .0255 to .0265. Now I am a bit of a fanatic about gapping my plugs. What gives?

Thinking back to all the trouble we have had with the stock gaps from the factory. This pops into my head. 

The gaps are changing. That is my working theory for the moment. Heat cycling? Something else?

This forum is the resource that can see if this is indeed true or partially true. Has anyone changed plugs in the last few thousand miles?
Pop them out and recheck those gaps, then post the results on this thread.

Any and all comments are greatly appreciated. I am no rookie to wrenching on cars. This is a brand new problem for me. 

Rob


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## jblackburn (Apr 14, 2012)

Gaps usually increase, not the other way around. What kind of tool are you checking them with?


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## newsguy99 (May 24, 2013)

I used to check with that little round thing setting at the counters for a buck 99. Then, I found a real gap tool.
Those rounds things are CRAP!


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## Champagne Jam (Feb 3, 2016)

I used the wire type. I always take my time to get very close. My friend has one of those snap on auto gappers. He refers to it as his spark plug breaker.


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## Blasirl (Mar 31, 2015)

Here are my two favorite spark plug (sorta) threads... maybe something in here will help.

Paid $600+... should've probably joined this community earlier and saved that money


Unfortunate dyno experience


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## Champagne Jam (Feb 3, 2016)

So if someone has the time and inclination to check the gaps after 3 to 5k miles. That would be helpful. The more the merrier. Data points and all that.
I already know what the gap is supposed to be and how to check it. YMMV.


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