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Discussion Starter · #1 ·
Just replaced my spark plugs with NGK BKR6EQUP at 100K miles on my 2000 323 Ci AT. I was getting about 26-27 MPG, but after I installed the new plugs, I'm only getting 23-24 (90% freeway)!!! I bought the plugs online at www.autopartsexpress.com, NOT from the dealer. Also, I didn't torque download the plugs to specs. The car now runs a little smoother, and slightly more quicker.

Any ideas? Thanks!
 

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King of Rear Clunks
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These plugs don't/can't be gapped, as they're surface firing plugs. They're the right factory plugs for the car, so I'm wondering if something else is wrong. Too much (if any) anti-sieze? If the antisieze is non-conductive, it would present a grounding problem for the plug. I'll be putting these in next week so we'll see what happens to me.
 

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Discussion Starter · #4 ·
It's platinum. I didn't put any anti seize...read some post that says not to put anti seize. It may cause conductivity problems.
 

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aktam said:
Just replaced my spark plugs with NGK BKR6EQUP at 100K miles on my 2000 323 Ci AT. I was getting about 26-27 MPG, but after I installed the new plugs, I'm only getting 23-24 (90% freeway)!!! I bought the plugs online at www.autopartsexpress.com, NOT from the dealer. Also, I didn't torque download the plugs to specs. The car now runs a little smoother, and slightly more quicker.

Any ideas? Thanks!
Perhaps a vacuum pipe was pulled off while you were doing the work?
The engine map needs to adjust due to slightly different firing characteristics of the plug, this should optimise quite quickly though?
With the increased smoothness of the engine due to the new plugs, you are using more throttle than before, consequently using more fuel, but it seems like you were using the same amount of throttle as before?
The measurement of fuel consumption is not accurate enough? - Using the OBC and not travelling the same route under the same traffic and weather condiions would lead to significant inaccuracy.
 

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Discussion Starter · #6 · (Edited)
I only drive to and from work on the same road so road condition is the same. I tend to drive even more conservatively now just to see if I can get the mpg up but no luck. I was very careful not to pull any hose when changing the plugs. I wonder if buying the plugs at the dealer would make a difference since they costs twice as much. I ones that I took out did have BMW stamped on, but both have same NGK part number. Also, would the failure of torquing the plug to spec cause this to happen too?
 

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King of Rear Clunks
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As long as it's not loose, it doesn't matter if it's torqued to exact spec or if it's s lightly off. These plugs aren't the traditional kind with the single ground electrode, so the 'tweak' on some cars where you want the ground to be pointing a specific direction inside the combustion chamber should be a non-issue.

You may want to double-check the old plugs to make sure they all have their original crush washers on them, and didn't accidentally leave one inside.
 

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I am suprise at all these answers that are being posted here..... :thumbdwn:

PLANTINUM sparks plugs can be GAPPED. There should be a specific range for you 323. Checked the gap.

Only irridium spark plugs cannot be gap (pre-gap) because the firing tip is so thin, you run the risk of damaging when if you gap it.
 

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mickey513 said:
I am suprise at all these answers that are being posted here..... :thumbdwn:

PLANTINUM sparks plugs can be GAPPED. There should be a specific range for you 323. Checked the gap.

Only irridium spark plugs cannot be gap (pre-gap) because the firing tip is so thin, you run the risk of damaging when if you gap it.
The NGK BKR6EQUP is a multi-ground plug with 4 side electrodes and semi-surface firing (as previously mentioned), the gap is pre-set, and can't be changed by any conventional method, as it depends on the spark travelling along the surface of the insulation as much as through the air-gap. If the electrodes are bent or damaged on this type of plug, the plug should be replaced.
 

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jsc said:
The NGK BKR6EQUP is a multi-ground plug with 4 side electrodes and semi-surface firing (as previously mentioned), the gap is pre-set, and can't be changed by any conventional method, as it depends on the spark travelling along the surface of the insulation as much as through the air-gap. If the electrodes are bent or damaged on this type of plug, the plug should be replaced.
IT's IS NOT PREGAP:

http://www.partsamerica.com/ProductList.aspx?parttype=960&ptset=A&searchfor=Spark+Plugs

Look at that for a 323i, spark plugs. ONLY NGK plugs that are pregapped are the IRRIDIUM, it clearly states do no regap. The NGK BKR6EQUP is plantinum and CAN BE GAPPED. And the specified gap range for a 323 is .032
 

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King of Rear Clunks
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According to Auto Parts Warehouse the NKG BR6EQUP plugs are set at 0.032 by NKG. I didn't check them before installing so I hope they're right.Even if they weren't I'm not sure how I would go about setting them since they are 4 pronged.
 

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Donkeybike?
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Never heard of gapping a 4 prong spark plug but I doubt that it would have any affect on your gas mileage.

My 323ci just turned over to 105k miles today and my gas mileage has unexplicably also gone south. :dunno:

If I find the reason I'll definitely post as to why.
 

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Kaz said:
These plugs don't/can't be gapped, as they're surface firing plugs. They're the right factory plugs for the car, so I'm wondering if something else is wrong. Too much (if any) anti-sieze? If the antisieze is non-conductive, it would present a grounding problem for the plug. I'll be putting these in next week so we'll see what happens to me.
Did you install the NGK plugs( BKR6EQUP)? Did you notice a decrease in mileage? I am about to purchase these plugs. I am hoping the factory gap is correct for my 330 as these cannot be gapped in any way....

Ed
 

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I have an E36 316i - You can't ask for a bigger difference betweens cars than that. And you won't be suprised to discover how I got on to this website - typed "poor gas mileage BKR6EQUP" into Google.

OK, so I am having the same exact problem, with poor gas mileage and its more significant - however the car has been much, much smoother and significantly faster.

I knew it had to be the plugs, because I had the car serviced at BMW, 72,000 Miles - all was good, besides bushings and a few bulbs out. I got the car back and she was fine - no missfires or anything.

But then I downloaded BMW's ETK and TIS (Parts Catalogue) - and I discovered these "High-Powered" Plugs from BMW. I bought the plugs and fitted them at 77,000 Miles.

Part Numbers from BMW: BOSCH(12 12 0 141 871) & NGK(12 12 9 071 003).

Essentially, BMW get BOSCH and NGK to make these plugs - I went for the NGKs. When I got the plugs it read "BMW - NGK" and engraved was the product code "BKR6EQUP", so these are the exact same ones as we're talking about.

I thought it could be my car, but looking at what you've mentioned it could just be the effects of the spark plugs - nothing faulty, just how it is.

Let us know though if you find out if it's something other than just the plugs. PS: The tightening torque (as mentioned by BMW) is 25-30.
 

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My first reaction to this thread was "Geez, another Beemer bozo". However, there probably is some fact to this, and an explanation. In the first place, 0.032" plug gap is pretty nominal in todays world. Wider plug gaps, often up to 0.060" present a longer spark to ignite the flame front, and in cruise situations, this narrow gap could lead to misfire, and reduction in fuel economy. The opposite is true for acceleration..you often need a narrower gap because of increased pressure in the cylinder, it takes a higher voltage to fire the plug. As the plug wears with mileage, the gap naturally increases, and sharp edges wear away. Thus it is quite possible that the situation described could occur. But not due to where you bought the plugs. Also, did you drop a plug and bend one of the electrodes? If 3 ground electrodes are 0.032, and one is 0.020, it's gonna fire to the closest one all the time, and possibly cause a subtle misfire at cruise.

Most new electronic engine management systems have a misfire detection program, that works with the crank position sensor detecting subtle changes in the rotational velocity of the crank. In practice, these programs only detect massive misfire, such as with a plug wire off or dead coilpack.

Another possibility is, since you seem to have more power on acceleration, are you testing the acceleration more than you did previously?? If so, have fun! And your question doesn't place you in the bozo category.
 

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Simple O2 sensors

Have you changed your Pre-Cat O2 sensors?? Just like the plugs they are to be replaced at 100K also. As they wear they become insensitive and tells the computer the mixture is leaner that it actually is. The computer compensates by making the mixture richer thus lowerering MPG.

Also believe they have switched to the winter blend of fuel in many parts of the country which historically gets lower MPG.

While the plugs 'CAN' be gapped, believe they are pre-gapped at the factory and there should be no need to change it.

Finally on the anti-seize compound. This is only for the next time you want to remove the plugs. If you did not use any, 100K miles from now it may be impossible to get the plugs out (they may actually snap off).

And it seems as most have better luck with the OEM NKG's than Bosch so you have the best plugs.
 
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