[obermd]

If you start to notice spark blowout during WOT it's time to take care of your plugs. I wasn't able to get to my spark plugs for three weeks and I noticed my daily commuting fuel economy dropped by about 10%. Even though I don't drive in WOT that much the plugs weren't igniting the fuel as well and I was leaving unburned fuel to go into my exhaust system.

 

[obermd]

Spark blowout is felt as serious power drops at higher RPMs while under WOT but the car performs fine otherwise. As the spark plug gaps continue to grow the "high" RPM drops closer and closer to cruising speeds of 1800 - 2500 RPM. It usually is first noticeable above 4000 RPM and then progressively at lower engine speeds.

 

[obermd]

The world of sparkplugs is as varied as the people using them.... There are what is considered generally accepted best practices. as indicated above.

one thing to think about, perceived spark blowout and misfires could very well be the ECU responding to knock detection and it's movement the spark timing, which at times can be a significant loss of power with a slow return to normal.

Spark blowout and knock detection feel different. Knock detection feels like pulsing in the throttle and doesn't impact engine speed. Spark blowout is a longer power drop and can actually limit engine speed in more severe cases.

 

[obermd]

So why is everyone saying .028" gap when ALLdata and many other threads on here state .032"-.035" is actually correct?

Your AllData information is out of date. Read the following two threads for why:

http://www.cruzetalk.com/forum/10-g...cial-statement-regarding-spark-plug-gaps.html

and

http://www.cruzetalk.com/forum/34-gen1-1-4l-turbo/46833-new-copper-spark-plugs.html

XtremeRevolution, with the assistance of over 100 CruzeTalk members, determined there was a problem with the spark plugs in the 2011 and 2012 Cruze. He got GM to take a second look at the spark plugs in the Cruze and their response is in the first link above. The second link is my measurements and calculations supporting GM's response.

 

[obermd]

Set your spark plugs to 0.028" regardless of type. Replace them when the gap reaches 0.038".

 

[obermd]

I will be gapping them back to .028" then, I currently have 73K on the car, so will need new ones in 20K or so anyways.

At this point if you're going to regap them I'd go ahead and purchase and use new plugs. Take a look at the lower two sections in my copper plugs post. I go into the gap growth calculations based on the OEM plugs there.