I'm sure it's been discussed a lot, but I searched the forum & can't find anything.
I got new plugs put in, my mechanic gapped them at .040. I know Scion recommends .032, should I have them taken down?

What are the Pros & Cons of .032 vs .040?

Thanks!

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This was Discussed long ago in my Thread from 12-15-2007:

https://www.scionlife.com/forums/sci...6/#post2147992

IMHO, .032 is the way to go.

MR_LUV

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Thanks Mr Luv. In your opinion what are the cons of using .040 vs .032?

 

Refer to, Again:►► NGK Iridium plugs and the Proper Gap? ◄◄

sdsnybny: "With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme.
Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think".

tanakasan: "IMHO, NGK plugs should be gapped to NGK specs. Three times the life span for the iridium sounds good to me! Slower wear means it will stay in the ideal gap zone longer".

Jan06xB: "spark voltage it proportional to the spark plug gap because the coil will generate an increasing voltage to the plug until it jumps the gap or arcs inside the coil or insulation of the plug.
The smaller electrode of the Iridium plug produces a more concentrated e-field and lets it spark easier and at a slightly lower voltage than a bigger electrode with the same gap.
If you gap the plug too big they will misfire under heavy load and probably damage the coils".

IMHO, I find many so-called 'mechanics' to be too lazy to try and properly gap your plugs. Many just take the plugs out of the box w/o doing a thing.

Therefore, you will see plugs at .038 or .040. For things to be done right, you need to do it yourself.

Always get a Spark Plug Gap Gauge and Spark Plug Gap Wrench and Set it either to your Manufacturer's Specs for OEM plugs or Aftermarket Specs for Aftermarket plugs.

MR_LUV

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hi,
i had replaced my stock plugs with the NGK Iridiums. no adjustment just .038 out the box. it ran ok...
since im one of those never leave it alone types.....
after a week i gapped them @ .040. BOO!!!! rough idle all day, constantly dropping to about 500 rpms and shaking at redlights even in neutral.

after another week i gapped them back to to .038.... MEH it got better...

week 3 i gapped them @ .032 like MR LUV suggested and she just purrrrrsssss. no dip in rpm, little shake, a slight bump in MPG.

dont forget to let the computer relearn before you drive away.