i know the OEM is

Standard (New): 1.0 1.1mm (0.039 - 0.043 in.)
Service Limit: 1.3mm (0.051in)

i am just wondering what you all tend to use ?


and have any of you ever experimented with diff gaps on the stock plugs ?

and i know your not suppose to adjust them, but jjust check, i am just wondering !

 

if you are going to put them in and leave them there for 100k miles without checking them (don't do this) then you might as well start on the low end of the spec, if you aren't using pre-gapped plugs. They will open up over time and will be pretty large by the end of service.

I put mine in at .043mm recently, I plan on checking the plugs once a year and at least once every two years. The larger gap within the spec. will get you the best performance IMO. There won't be a huge difference either way but youll get the best results from .043. My factory plugs opened up to over .051" within 55k miles so they were out of spec before the rated mileage.

 

nice ! i just bought a wire gapper tool and the lowest it has is 0.040

why do you say 0.043 is the best ?

 

yea, never really understood he gap. some said the more whp u have the smaller the gap or the lager the gap. someone please explain.

 

generally speaking you run the largest gap possible without experiencing misfire or blowout and you will maximize hp and fuel economy. This applies to boosted setups as well as naturally aspirated. As long as you aren't experiencing firing problems (i.e. the spark is able to jump the gap) you will burn a higher percentage of air fuel mixture and it will burn quicker with a larger gap. When you are talking about the factory spec. range on a relatively stock naturally aspirated motor the .043" will get you better performance. The s2000 motor has absolutely no issues running .043", so you might as well run it to the higher end of the spec.

On my 04 Dodge SRT4 it came from the factory with gaps of .054" running about 12 psi boost, that was a pretty high gap for a boosted engine, and it worked.

 

what gapper do you have ? i bought one today at advanced auto and it dosent have 0.043

 

semi off topic: what kind of plugs are you guys using?

 

oem

 

I run NGK copper plugs in all my cars.For my stock 03S,I run either BKR7E or BKR6E.Gap @044.Adjust the heat range +/- 1 range depending on how the car is driven and how the plugs look.

I check plugs every OCI and usually change them every 10k.Copper plugs are about $2ea and since it takes less than 30 min to change all....why not.

With a smaller gap,you will get VERY SLIGHTLY better perf & worse econ.Larger gaps are the opposite.

As always,IMO.

\rlr

 

I only use a wire type of feeler guage. Some sizes are hard to find, I know the feeling. If you don't have .043" it must have something close such as .044 or .042. Those would be suitable to use in place of .043", otherwise source out a new guage that has the specific size. hth.