What About Spark Plugs???

maxhonda99maxhonda99 Member Posts: 1,289
edited March 2014 in Honda
I was looking for some information about spark plugs and didn't see any discussions about it, so I thought I would start one.

I'm looking for some information(and I think other people would be helped also) on spark plugs. I've heard conflicting information on different types of plugs.

A couple of people have recommended going to cooper plugs from platinum. Why? They say the cooper plugs will give a smoother idle. They also say platinum plugs only real advantage is longevity of the spark plug.

What's the truth? Anybody know?

What's best? Cooper? Platinum? Iridium?


  • swschradswschrad Member Posts: 2,171
    the whole conductor path is not platinum, just the electrode tips. look at a "double platinum" plug, you will see bumps on the center electrode and on the grounded "J" electrode. those bumps are all the platinum you get for the price, my man. the purpose is that they are more resistant to electrical erosion and also introduce a catalytic effect, which may help the spark start at those two bumps, so wear and deposits at the bumps are greatly reduced.

    iridium, osmium, tungten/rhenium, and other hard metals allegedly provide the wear resistance but should not provide the extra impetus to force the spark to occur at that point that the catalytic effect of the platinum does.

    none of them are the best electrical conductor. silver is. copper is next. iron is way down the list, and then the rest of these fine rare metals come along about where the guy sweeps up at the end of the parade. at 40,000 volts, the differences are not major, there is still plenty of voltage to whack a spark across. that is, until the plug is worn to double its initial installation gap.

    if you don't mind changing plugs more often than recommended, copper plugs are fine. it's even better if you pull 'em and regap 'em regularly, just like 1957.

    if you don't want stumbles at idle under load, with a trailer on, platinum might buy you something there.

    if you don't care, buy for value and change 'em at least every 40,000
  • swschradswschrad Member Posts: 2,171
    all you're doing is putting a hard, catalyzing metal at the point of desired spark. if they made aluminum plugs, you could install them... every 500 miles ;)

    insuring, of course, that you put in the correct plugs for the engine application as defined by brand, model, and year in the cross-reference manual. putting in plugs too short or too long can cause big issues and lousy performance, if any.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I have this rule which has never failed me. I use the spark plugs made in the country of origin of the car.
  • swschradswschrad Member Posts: 2,171
    I put in what the car came with. there is an occasional issue based on time of day and when I go back to the cities when I work on my sister's. but I go with the OEMs. no explaining if things go awry that way.

    but having said that, any brand-name plug made to the correct tooling that fits the spec will work fine for some number of miles.

    I suspect you're right, shifty, in sticking close to origin, so there is a real good chance the guys trying to match the standards can READ what they are. remember the last mars explorers? nobody used "French yardsticks" at home, and they augered in because of the difference.
  • roadrascalroadrascal Member Posts: 35
    Mr_Shiftright says:
    "I have this rule which has never failed me. I use the spark plugs made in the country of origin of the car."

    So what if you have an "American" car with a "Foreign" engine in it? I have found that it's usually best to use whatever plug originally was installed. My older Dodge had a Mitsubishi engine that came with Nippondenso's and ran best using that brand of plug.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    rascal---same-o, same-o....Japanese engine in American car gets NGKs or Nippondenso or whatever came with the car's engine.
  • 0patience0patience Member Posts: 1,712
    One pretty good rule of thumb to go by is to use what the engine originally came with.
  • alcanalcan Member Posts: 2,550
  • zueslewiszueslewis Member Posts: 2,353
    I'm looking to swap the plugs on my PT Cruiser GT (turbo) - same engine as the Neon SRT4. I was shocked when I found Champion plugs in the engine - I quit using them years ago.

    Nopi has NGKs for $15 a piece for my car - weird bunch of facts in place - bargain basement in the car now, astronomical to replace.
  • wilcoxwilcox Member Posts: 582
    Does it seem to need plugs already? Those turbos must be hard on plugs.
  • zueslewiszueslewis Member Posts: 2,353
    I'm at 23K and have a high-speed miss.
  • maxhonda99maxhonda99 Member Posts: 1,289
    So then, Probably Platinum plugs it is! Now which platinum to get? Cheapo Bosch at like $2 a plug, Bosch Platinum +4, NGK Platinum's?
  • swschradswschrad Member Posts: 2,171
    I suppose they fought hard to get in there because DC has never owned a plug company. I thought they used to use Prestolite a long number of years ago, but it was champions by the 60s.
  • alcanalcan Member Posts: 2,550
    For applications that use copper plugs as OEM I've had good luck with Bosch Platinum's, especially for engines with high compression pressures like you'd have when your PT's turbo is spooled up.
  • zueslewiszueslewis Member Posts: 2,353
    in my '87 Corolla FX-16 and 4 Mustang GTs - I like the way they burn.

    Now, all I have to do is find them for my car - Pep Boys, Autozone, Napa, etc - NO ONE has plugs for this thing yet.
  • swschradswschrad Member Posts: 2,171
    just to check one online catalog, autolite 3923 series plugs will fit the V6 engine, 3.7 Liter, designated engine K by dodge.

    we could play that game all day with each brand and each engine.
  • zueslewiszueslewis Member Posts: 2,353
    I have a PT with a 2.4 (4cyl) turbo...
  • swschradswschrad Member Posts: 2,171
    that has now been deleted. asking what his truck used.

    while DCX/chrysler usually has been using champions, they could have used anything in any particular car, especially if the engine was from another maker. so it's really hard to tell.

    you can be sure a ford comes with motorcrafts in it (unless maybe you had a yamaha-tweaked probe or something, it might have NGKs standard), and I would be shocked to see standard plugs in a GM that didn't come from AC Delco. but mopars don't have ownership in a plug outfit, and they could take whatever comes along if they wanted to.
  • isellhondasisellhondas Member Posts: 20,342
    I can remember when a set of spark plugs were good for about 12,000 miles. I remember what a difference a new set of plugs would make!

    And, I remember points too.

    I picked up a couple of spark plugs in our shop the other day that had come out of an Odyssey with 90,000 miles. Original plugs and they still looked fine.

    As far as brand. I was always taught by the old masters in the business to use what came with the car from the factory and to NEVER, EVER use Champions!
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