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subaru_terrence
10-23-2009, 03:57 PM
I tried the search button but didnt have much luck. I guess I am just bad at searching.

I have to replace my spark plugs soon and I already have the NGK copper ones in my garage.
i THINK they are pre-gapped at .044 but I have read other forums that I need .028? However, I am not too sure which one I should go for since I cant find a solid confirmation.

Can anyone please confirm me whether i should gap them at .044 or .028?
It is a 2.5L NA engine
green97gt
10-23-2009, 06:07 PM
.028 seems awful small...

either way its not the end of the world.

ide go .040 if you notice issues, regap.
Matt S.
10-23-2009, 06:33 PM
I don't think I ever messed with NGK plugs. Just throw them in and forget it(on a totally stock grocery getting 2.5L :smile: )

The .028 is for turbocharged 2.5s.
Grafton
10-23-2009, 07:07 PM
the book says .039 to .043
set'em to .40 and check every 10k miles
subaru_terrence
10-23-2009, 07:27 PM
reason I am asking because my car is tuned with perfect power and I notice i have misfire.
however, if i run stock ecu, it is fine. I am just trying to see if it is the problem of the spark plugs
httrdd
02-13-2010, 01:42 PM
the book says .039 to .043
set'em to .40 and check every 10k miles

Would this be the same with my 99 LGT? I just bought ngk v-power plugs and would like to check the gap! I am running Magnacor competition wires with them and a MSD ignition.
Huffer
02-13-2010, 02:35 PM
reason I am asking because my car is tuned with perfect power and I notice i have misfire.
however, if i run stock ecu, it is fine. I am just trying to see if it is the problem of the spark plugs

If the variable is the ECU/piggyback, then it's the ECU/piggyback tune, not the plugs. The plugs don't magically change gap when you switch ECUs.
rougeben83
02-13-2010, 07:55 PM
I'm guessing the pp6 is keeping your ECU from being able sense misfires and change the timing accordingly...but yeah set the plugs to .40. Never hurts to check the gap even if you can't adjust it (like on the NGK iridiums)...
ouch1011
02-14-2010, 11:41 PM
You can set the gap on any plugs...as long as you use the proper gapping tool.

Anyway yeah, .028 is way too narrow for any newer N/A engine. That would be for a turbo/sc engine.