Kizashi Club

Northernstar wrote:Thnx for the write up! Is there a difference between higher end spark plugs and the lower end ones??

You mean like copper vs platinum/ iridium? They'll need to be replaced more often (something like 40000km vs 100000km), but as long as they spark correctly your engine will be happy.

Northernstar wrote:Thnx for the write up! Is there a difference between higher end spark plugs and the lower end ones??

Aside from lifespan, no difference between materials. I've experimented with them on my GTI and there was no measurable changes in performance.

I stick to NGK iridium plugs now for the longer lifespan. Cost per mile is about the same or less than coppers, and you spend less time replacing them.

As for brands, I would imagine they're all similar as long as you're in the correct heat range. I prefer NGK and Denso

The whole you don't have to gap the plugs cuz they're pre gapped is complete utter bull **** . I changed my plugs back in march to those exact plugs cuz that's the plug it calls for right ? Well the gap on those plugs is .45 or .045 can't remember how it goes but the coils and computer is set to read it at .44 or .044. It doesn't seem like much of a difference right ? Wrong it took all of three months for it to start to missfire and then it got bad quick ( I.e. it cut cylinders out while driving) took it to dealer ran test on coils fine changed spark plugs and put to proper gap has ran perfect ever since

Armykizyguy92 wrote:The whole you don't have to gap the plugs cuz they're pre gapped is complete utter bull **** . I changed my plugs back in march to those exact plugs cuz that's the plug it calls for right ? Well the gap on those plugs is .45 or .045 can't remember how it goes but the coils and computer is set to read it at .44 or .044. It doesn't seem like much of a difference right ? Wrong it took all of three months for it to start to missfire and then it got bad quick ( I.e. it cut cylinders out while driving) took it to dealer ran test on coils fine changed spark plugs and put to proper gap has ran perfect ever since

Is that with your modified ignition system- or prior to the change?

Spark plug gap is pretty much meaningless anymore. Used to be you could tune your engine a little bit by opening or closing the gap. Now, with the iridium/platinum plugs and the super high voltage ignition systems, as long as there is a gap there's nothing you can do to your ignition system which will make any difference.

Armykizyguy, you had a bad plug, there's no way .001 difference in gap was causing any problem. .005 difference wouldn't do that.

Woodie wrote:Spark plug gap is pretty much meaningless anymore. Used to be you could tune your engine a little bit by opening or closing the gap. Now, with the iridium/platinum plugs and the super high voltage ignition systems, as long as there is a gap there's nothing you can do to your ignition system which will make any difference.

Armykizyguy, you had a bad plug, there's no way .001 difference in gap was causing any problem. .005 difference wouldn't do that.

I agree that such a small difference in gap wouldn't cause any misfires or issues. Hell, 0.001" is probably within the margin of error when gapping

You don't need to gap IF and ONLY IF you use Platinum or Iridium plugs.

If you use copper plugs, you should be gapping.

I have experimented with gapping and not gapping platinum and iridium plugs. There was no difference in performance for a few reasons:

The thinner center electrode in plats/irids offers a more efficient spark since there is less material to arch from to the ground/side electrode. In addition, I have found that many plats and especially iridium plugs come pre-gapped to nearly an ideal gap anyways for the application.

Also, the main reason why gapping is NOT recommended is not so much for the already efficient nature of the spark. It's actually so that people don't accidentally damage the thin and brittle center electrode of plats and especially iridiums while attempting to gap them. Basically, the risk outweighs any benefits you may gain in gapping these efficient plugs.

Copper spark plugs are a different story. Their center electrodes are much wider than plats/iridiums and they don't often come optimally gapped. For these reasons, gapping them is necessary and also safe to do.

Lastly, the type of plug you use does not increase power. It merely effects how long optimal spark is maintained. If you notice an increase in power from changing plugs, it's not actually an increase, but more a restoration of original power. Whether you use a copper or iridium plug will have little effect on power for a normal engine. The difference is how long the optimal gap, therefore spark, will last. Iridiums offer a significantly longer lifespan.

Prior to the change. They where Ngk plugs iridium too and all coils where perfect. Replaced them anyway after I put the different plugs in. I now use autolite xp iridiums not a problem

gotta change mines soon. Gonna use e3 spark plugs tho. Heard alot of good things about them

Any good things you're hearing are advertising hype. Iridium and Platinum last longer, other than that, a plug is a plug.