I've read two different spark plug gap settings for B16a. ~.044 and ~.051. Why is there 2 different specs and which is the better one to use?

I know one is for JDM motors and other is for USDM and wondering if the different ignition maps on the ecu's better utilize the spark plug gap accordingly.

 

go with the tighter spec. i've used both and made no difference.

 

bump for other opinions cause i wanna know too

 

Normal NGK's for B16's use .44 gap (they are pregapped)

I would assume its not due to any ECU mapping, rather the ability to run larger gap due to thier much higher octane over there. Use the .44.

 

i also read in another post that Rocket suggested .038". I always run 93 octane and I have oem dizzy style ignition.

 

so, i think i ruled out the .051", and my plan is to run .040", kinda between the 2 specs. any objections or other thoughts?

 

Id go with the .040, as most Hondas Ive seen the specs on have used that gap... And def go NGK, but just cuz theyre 'pregapped' check them anyway! I just did my brothers car, and the pregapped .040 were actually much smaller...

 

I gap at .040