Can spark plug brand affect mileage?

[Vikas]

You don't have to buy the OEM plugs from the dealer. Buy them from Amazon or mail order or even local parts store. You should be able to get under $10 for each plug; not cheap but still at half price as compared to dealer.

On Japanese car, stick with NGK or Denso.

 

[Bgallagher]

Originally Posted By: Vikas
You don't have to buy the OEM plugs from the dealer. Buy them from Amazon or mail order or even local parts store. You should be able to get under $10 for each plug; not cheap but still at half price as compared to dealer.

On Japanese car, stick with NGK or Denso.


+1 Also try rockauto. They carry a large amount and are generally reasonable.

 

[rcy]

Shipping cost to Canada (and duty / brokerage fees depending on how it's shipped) are ridiculous, sometimes costing more than the part ordered. I'll just grab the Denso from the dealer and contort myself into the engine compartment again...

 

[ARCOgraphite]

"Fancy" Bosch plugs are GARBAGE in std PCMO use period. The Bosch Copper core STD inconel plugs are good and cheap - but not for your app. Denso or Ngk and NOT NGK USA V-power junk.

 

[dparm]

Platinum is not used for performance reasons, it's used for LONGEVITY reasons. Same thing for iridium; exception being the special ultra-sharp Denso Iridiums with the 0.4mm tip.

 

[punisher]

Originally Posted By: rcy

How can one brand of spark plug, assuming same material (copper, platinum, iridium etc.)is used be any different than another brand when they both do the same thing - make a spark?


In a perfect world, yes.

I did engine performance at a dealership (stealership) for more years than I will admit. Spark plugs absolutely cause problems concerning mileage, idle quality, misfires, and overall driveability. It is not just a case of the wrong plug, but cases where the plug manufacturer's own parts application list was followed. Done plenty of missfire MILS on vehicles right after the customer had plugs replaced (sometimes 30K replacements on platinums) at a quickie-tune, go figure). They thought it would still be under warranty.

Now, with newer engines, I think some auto manufacturers are using the plugs to gather individual cylinder data to tailer injector pulse/timing and individual advance. Not exactly sure how the sensing function works (I think Jacobs holds some of the patents on it) but I have heard it is important to use the OEM plug.

 

[GMBoy]

Originally Posted By: Bgallagher
Originally Posted By: mattd
I would have used OEM denso plugs. Thats all we use in honda products. They do not seem to run as well with other plugs. I'd recommend changing them out.

Same thing with AC-Delco and GM vehicles. Other brands just don't seem to work. I'd swap them out. Also, how do the wires look? Did you dab some dielectric to ensure a good seal?


You do realize that AC Delco no longer makes their spark plugs? They are sourced out to companies like NGK, Denso, and Bosch.

But - to support your comment, aleast by getting the AC DELCO part you are get the exsct replacement specs as opposed to a wider range aftermarket plug that just "works".

Me personally, I got away from Delcos and use Autolites or NGK's when doing plugs.

 

[mechtech2]

Most mechanics won't use Bosch unless they came factory equipped with them.
Plugs can make a difference because if they are the wrong heat range, they can fail by fouling or overheating. If the gap is too small or too large, you get a weak spark or misfiring.
And if they are Bosch, you'll have problems anyway.

 

[meep]

Originally Posted By: punisher

Now, with newer engines, I think some auto manufacturers are using the plugs to gather individual cylinder data to tailer injector pulse/timing and individual advance. Not exactly sure how the sensing function works (I think Jacobs holds some of the patents on it) but I have heard it is important to use the OEM plug.


This^^^

They use the plug to sense the combustion health -- IDK if it reads miniscule voltages present during the burn or if it looks at how the spark breaks down once flame is achieved, but it does read. Probably some high freq resonance characteristics of certain plugs could conflict with how the ecu reads that signal.

I do not think wasted spark systems have this intelligence, but 1-1 COP systems can.

 

[hypervish]

NGK or Denso only.

 

[wirelessF]

When I did the plugs on my 02 Chevy 5.3L, I bought Denso Long Life spark plugs with a .040 gap, way different then the .060 gap that it calls for. The old plugs I pulled out were Denso double platinums which had a different spec number than the long life I put in.

LL (new): ZTJ16R10
DP (old): PTJ16R15

And I got the plugs for $6 each so it's a great deal on OEM replacement plugs. Kinda went overboard when I replaced the wires with MSD Super Conducters though.

 

[ARCOgraphite]

Shouldnt have use the MSD if they are mag. They can be noisy and magwire may exhibit differenent (and possibly destructive) resonance than the simple R carbon f-glass low L cable. Low impedance is not necassaty on commercial applications, good quality insulation is - as you used to find in PACKARD brand wire. Even the Japanese OE had imported packard bulk wire to use on JDM applications in the past it was so good on reducing crossfire and leakage. Making good wire seems to be a big mixture of art with the science.

 

[pbm]

Originally Posted By: ARCOgraphite
If you have waste spark ignition (e.g: one coil firing 2 plugs and one plug fires "backwards") then having a non fine wire in the negative firing hole is important to reduce misfiring and improve mileage and torque. This is common on certain V6 where three coils are used to fire six holes. With COP (individual Coils On plug) they are not sensitive to firing direction but more sensitive to gap and ignitability. YOu want Ir finewires (denso or NGK) on engines with small COP coils for easy ignitability.



Arco: Would any of these vehicles have a 'waste spark' ignition?

2008 Corolla, 2008 Elantra, 2005 Ion, 2011 Cruze

 

[Bamaro]

Brand - no, model - maybe.

 

[OVERKILL]

Originally Posted By: ARCOgraphite
Shouldnt have use the MSD if they are mag. They can be noisy and magwire may exhibit differenent (and possibly destructive) resonance than the simple R carbon f-glass low L cable. Low impedance is not necassaty on commercial applications, good quality insulation is - as you used to find in PACKARD brand wire. Even the Japanese OE had imported packard bulk wire to use on JDM applications in the past it was so good on reducing crossfire and leakage. Making good wire seems to be a big mixture of art with the science.


Having used the MSD wires on numerous vehicles, they are excellent. Have multiple layers of HEAVY insulation and are generally very well put together.

 

[mechtech2]

They use special coils to monitor the voltages. Complex and costly, but it works.
Factory plugs are a must, with these self monitoring systems.
http://delphi.com/manufacturers/auto/powertrain/gas/ignsys/ionized/

 

[ARCOgraphite]

Originally Posted By: OVERK1LL
Originally Posted By: ARCOgraphite
Shouldnt have use the MSD if they are mag. They can be noisy and magwire may exhibit differenent (and possibly destructive) resonance than the simple R carbon f-glass low L cable. Low impedance is not necassaty on commercial applications, good quality insulation is - as you used to find in PACKARD brand wire. Even the Japanese OE had imported packard bulk wire to use on JDM applications in the past it was so good on reducing crossfire and leakage. Making good wire seems to be a big mixture of art with the science.


Having used the MSD wires on numerous vehicles, they are excellent. Have multiple layers of HEAVY insulation and are generally very well put together.
Were they OEM replacement resistor wire or magwire using a MSD box on a distributor? Ive done thousands of tuneups and niether MSD or ACCEL magwire worked in OEM applications as well as stock OEM wire in good condition. Ive never run MSD box on our competition engines - so I cant talk about 7AL box on a drag or roundy-round modified car. If they work where you tried thats good though - ignitions can be ( and usually are) flaky and fragile things.

 

[OVERKILL]

Originally Posted By: ARCOgraphite
Originally Posted By: OVERK1LL
Originally Posted By: ARCOgraphite
Shouldnt have use the MSD if they are mag. They can be noisy and magwire may exhibit differenent (and possibly destructive) resonance than the simple R carbon f-glass low L cable. Low impedance is not necassaty on commercial applications, good quality insulation is - as you used to find in PACKARD brand wire. Even the Japanese OE had imported packard bulk wire to use on JDM applications in the past it was so good on reducing crossfire and leakage. Making good wire seems to be a big mixture of art with the science.


Having used the MSD wires on numerous vehicles, they are excellent. Have multiple layers of HEAVY insulation and are generally very well put together.
Were they OEM replacement resistor wire or magwire using a MSD box on a distributor? Ive done thousands of tuneups and niether MSD or ACCEL magwire worked in OEM applications as well as stock OEM wire in good condition. Ive never run MSD box on our competition engines - so I cant talk about 7AL box on a drag or roundy-round modified car. If they work where you tried thats good though - ignitions can be ( and usually are) flaky and fragile things.


These were on EEC-IV Ford applications (TFI). Distributor based, the OE wires were resistor core.

I've used them with and without a box and they performed flawlessly either way. I currently have them on my Town Car (with a 6A).

 

[rcy]

Well, I replaced the Bosch Fusion with the Denso tonight. Seems to drive and idle the same. Won't know about mileage until I drive a bit.

I'm really thinking plugs can't make that much of a difference, but I can sleep easier at night knowing I have the OE plugs in.

 

[N7Quarian]

Brand? I don't know. But I did change the NGK R 4 Tip Platinum's with the original Denso K20 U Grooves and the car idles a little worse. I put back the NGK's and it was fine again. I don't even know if the NGK's were in the right heat range. I just tried them because they were the EXACT plugs that my BMW uses.