deathstar

almost forgot, switched to slipery super synthetic oil too, less friction = more power

scdroptop

iTrader: (1)

Again I don't have any proof other than a feel and my experiences with dozens of sports cars driven sporadically as a third or fourth car for the past 20 years like rx7s 300zs supras s2000 g35 legends sc300/400 and hae seen improvement in upgrading to the next level of plugs personally. The data and research that ngk posts about carbon buildup on shorter drives and less miles coupled with th new choices in plugs since our 11 year old cars spark plugs were chosen makes sense to me to look further.

For the money and DIY my point Is that these particular plugs are a nice choice o increase your cars responsiveness, acceleration and overall feel for performance!

jzwu

It is possible that worn plugs are harder to spark thus putting stress on the ignition system and causing hesitation, etc.

Once the plug sparks it is the same performance. The symptoms are more related to the ignition system load, such as requiring a higher voltage.

lexie

Long time CL member & LS owner, just picked up a 2002 SC430 this past July; I'm wonder what is the part number of the plug you purchased?

Owner's manual NGK part number: IFR6A11

but at NGKsparkplugs.com, it says IFR6T11. I wonder which is correct? And which one did you buy? Thank you.

gripau1

Iridium only last about 70k km compared to 100k km with platinum plugs.

scdroptop

iTrader: (1)

NGK Plug model # 4589, Catalog # IFR6T11. Got on eBay for $60 for all eight! $20 cheaper than Autozone.

And I will most likely change in less than half that like I did these! LOL

My buddy who is a porsche guy just changed his out on a super cream puff 2007 Boxster S and noticed a difference too. I've always "felt" like it made a difference. For $60 in parts and $150 labor to me a mod well worth it considering I've shelled out much much more than that on this car for other mods!

Lexicon1

I don't mean to be controversial, skeptics abound in life. A spark is a spark. No prob, to some that may be true. I am fairly invested in audiophile equipment and there are doubters in that hobby too. I can attest that I have been skeptical and ignorant about certain aspects of the audio experience and only after experiencing better quality equipment did I THEN realize quality made a difference. Example. I had an inexpensive Sony CD player. A CD player is a CD player. It just reads 0's and 1's, right ? Well, I finally succumbed to anecdotal observations that there are superior CD players and finally bought one. WOW, what a difference, information on my old CDs that I never knew existed was revealed. I also found this true with amplifiers etc etc.......my point is, when credible sources say that something they have experienced made a difference, it may be worth investigating and trying out yourself. I believe that short trips do adversely plug performance with time.
I will likely change my plugs in a few thousand miles..I have 75k on the SC.
Thanks for your suggestion
Just my two cents.

edmondt

I'm sold bought a set of 8... My 02 has around 200,000km and I don't think it ever has a spark change

GammaLex

I need one step colder which ones would those be?