Denso IK20TT pre gapped variation

[wing0]

I got 6 x IK20TT spark plugs from RA, came in two 4 pack boxes (with one missing 2 inner boxes). I believe the specs says they are pre gapped to 1mm or 0.04inch.
With a coin gap gauge, only 1 is reaching 0.04, they are in the range
0.036 x2
0.037 x1
0.038 x2
0.039 x1
The 1MZFE engine specifies 0.044 but that's for the old long life iridium without the needle platinum ground.
I would be fine with 0.04 gap, but wondering are the smaller gap ones ok to be installed?

 

[slacktide_bitog]

A coin gauge really isn't that great because of the inclined surface. Also, the gaps you measured are reasonably close to each other.

The smaller gap will be fine

 

[Leo99]

From a math perspective with rounding, they are all 0.04". In my industry, we round our results to align with the number of decimal places in the specification.

Is a coin gap gauge accurate to a 1000th of an inch?

 

[JeffKeryk]

From a math perspective with rounding, they are all 0.04". In my industry, we round our results to align with the number of decimal places in the specification.

Is a coin gap gauge accurate to a 1000th of an inch?

Depends on the operator, I imagine. Most gauges are...

 

[pbm]

I have found spark plug gapping tools to be often inaccurate. I have several of the 'coin' and 'hoop' types and get
slightly different readings from all of them....I'd say your fine installing them as they are.

PS: Can anybody suggest a spark plug gap tool that they feel is accurate?

 

[wing0]

Thanks all, installed them.
I would hope the smaller gap won't be an issue as these are supposed to wear out the platinum needle side faster and gap will increase with time.

 

[partspro]

I used to check random plugs from different Manufacturers, NGK, best, but remember, they arrive in totes, packed with other stuff

 

[wing0]

Mine came from RA and was well packed. I doubt it was affected by shipping.

 

[spasm3]

I don't use a coin gauge on anything other than what everyone calls copper plugs.

It's too easy to chip or mess up the thin precious metal tips. I use a feeler or wire gauge.