Need Concrete Answer As to Proper Spark Plug Gap

1QuikWS6 · 06-02-2016, 04:11 PM

Car is 2009 328iX E92 with N51 Build Date 2/2009

Looking to change out my spark plugs @ 60K mi

Purchased spark plugs P/N 12 12 2 158 253 NGK PLZFR6A-11S

Read thru a couple threads on plugs and never seem to see a concrete number as to the gap they should be set at - some say .040, some .043, some .044

Plugs are supposed to be pre-gapped from NGK. Using their P/N decoder the '-11S' refers to a gap of .044

I checked/re-checked all the plugs & I keep getting a pre-set gap of .041 max

Since these engines are so sensitive to plug gap what IS the gap these should be set at based on members with experience?

Thanx!

jpregione · 06-03-2016, 04:54 PM

I have an 09 328i with N51 engine and my chilton calls for .040 gap, I would think that as long as all plugs are the same your .041 will be ok.

kkasson · 06-03-2016, 08:56 PM

Most NGK plugs use a gap of either 1.0mm or 1.1mm. 1.0mm is ~0.40 inches, 1.1mm is ~0.43 or ~0.44 inches.

According to NGK, your plug is 1.1mm, i.e. 0.43 or 0.44 inches.

I wouldn't change it if it were 0.41. That should work fine.

roundle · 06-05-2016, 10:02 AM

Check the gap of your old plugs when you replace. Always fun to see how far out of spec they become after just 50K miles.

1QuikWS6 · 06-06-2016, 03:27 PM

Thanx guys - I'll just go with the .041 gap as received from NGK & see how it goes

Just a little confused as NGK site states that plug code should be pre-gapped @ 1.1mm/.044"

06-02-2016, 04:11 PM	#1
1QuikWS6 No 55mph 1622 Rep 8,476 Posts Drives: F32 435ix MSport Join Date: Jul 2009 Location: Blitzburgh, PA iTrader: (113) Garage List 2022 BMW M440ix Vert [0.00] 2015 BMW 435ix MSport [0.00] 2000 Pontiac Trans Am [0.00]	Need Concrete Answer As to Proper Spark Plug Gap Car is 2009 328iX E92 with N51 Build Date 2/2009 Looking to change out my spark plugs @ 60K mi Purchased spark plugs P/N 12 12 2 158 253 NGK PLZFR6A-11S Read thru a couple threads on plugs and never seem to see a concrete number as to the gap they should be set at - some say .040, some .043, some .044 Plugs are supposed to be pre-gapped from NGK. Using their P/N decoder the '-11S' refers to a gap of .044 I checked/re-checked all the plugs & I keep getting a pre-set gap of .041 max Since these engines are so sensitive to plug gap what IS the gap these should be set at based on members with experience? Thanx! __________________ F32 435ix//MGM//M Sport-Prem-Tech-Driver Assist-Lighting-Cold Weather-Dyn Handling Pkgs//M4 Black Lthr Int w/M4 Alum Blade Trim//HK w/Bavsound Stg3//763M//M4 Euro LCI Tails//M4 Mirrors w/CF Covers//AWCarbon CF F/R Spoilers-Side Splitters-Diffuser 6WB/ID6 HU+HUD/IND M4 Alcantara Armrest//PURE S2 Turbo//AA FMIC+DP//ER CP+TIC//3.5bar TMAP/TS DV//AWE Tuning Exh w/Blk Tips//Turner MS CF Intake//BM3 Cary Jordan Tune//MPerf Diff//PrecRW Ignition Kit
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06-03-2016, 04:54 PM	#2
jpregione Private 12 Rep 85 Posts Drives: 2009 E90 328i Join Date: Oct 2015 Location: San Tan Valley Arizona iTrader: (1)	I have an 09 328i with N51 engine and my chilton calls for .040 gap, I would think that as long as all plugs are the same your .041 will be ok.
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06-03-2016, 08:56 PM	#3
kkasson Lieutenant 187 Rep 589 Posts Drives: 07 BMW 328i, 08 BMW 528i Join Date: Jun 2015 Location: CA iTrader: (0)	Most NGK plugs use a gap of either 1.0mm or 1.1mm. 1.0mm is ~0.40 inches, 1.1mm is ~0.43 or ~0.44 inches. According to NGK, your plug is 1.1mm, i.e. 0.43 or 0.44 inches. I wouldn't change it if it were 0.41. That should work fine.
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06-05-2016, 10:02 AM	#4
roundle EXPAT 65 Rep 889 Posts Drives: 18 VW GTI;18 CX9;11 E91 N52 Join Date: Apr 2010 Location: USA iTrader: (0)	Check the gap of your old plugs when you replace. Always fun to see how far out of spec they become after just 50K miles.
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06-06-2016, 03:27 PM	#5
1QuikWS6 No 55mph 1622 Rep 8,476 Posts Drives: F32 435ix MSport Join Date: Jul 2009 Location: Blitzburgh, PA iTrader: (113) Garage List 2022 BMW M440ix Vert [0.00] 2015 BMW 435ix MSport [0.00] 2000 Pontiac Trans Am [0.00]	Thanx guys - I'll just go with the .041 gap as received from NGK & see how it goes Just a little confused as NGK site states that plug code should be pre-gapped @ 1.1mm/.044" __________________ F32 435ix//MGM//M Sport-Prem-Tech-Driver Assist-Lighting-Cold Weather-Dyn Handling Pkgs//M4 Black Lthr Int w/M4 Alum Blade Trim//HK w/Bavsound Stg3//763M//M4 Euro LCI Tails//M4 Mirrors w/CF Covers//AWCarbon CF F/R Spoilers-Side Splitters-Diffuser 6WB/ID6 HU+HUD/IND M4 Alcantara Armrest//PURE S2 Turbo//AA FMIC+DP//ER CP+TIC//3.5bar TMAP/TS DV//AWE Tuning Exh w/Blk Tips//Turner MS CF Intake//BM3 Cary Jordan Tune//MPerf Diff//PrecRW Ignition Kit
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