@
KYBubblehead
,
I went ahead and guinea-pigged it yesterday. Yanked my plugs, they were the original Denso iridium long lifes...the name is well-suited as these plugs had just under 184,000 miles on them and were still functioning just fine--that said, I'm glad I replaced them. The coil pack bolts were pretty corroded so I replaced them as well.
I chose the Denso Iridium TT 4702. I was a bit concerned about the gap being .040" compared to the OEM spec of .044" but so far no issues, no codes thrown. I attribute the difference in gap to more efficient detonation, maybe hotter spark too? but that's just speculation on my part. I looked all over the web for answers, talked to parts guys at dealerships and even called Denso, but the call went to some engineer's* (*i assume) voicemail so I never got an answer.
Either way, I noticed immediate improvement in throttle response, acceleration, quicker starts, smoother idling and--in general--smoother running throughout the rev range. I'm pretty happy with the change.
While I was at it, I cleaned the coil packs with MAF sensor cleaner, and put a thin coat of white lithium grease on the inside lip of the connectors as well as where the coil pack boots meet the coil pack--sort of in hopes that it would help seal out water or dirt but was probably pretty unnecessary. I think the lithium grease on the connectors is a good idea though and won't be in vain.
I can't speak to the change I might have noticed if I had chosen the Denso Iridium Power rather than the Iridium TT, but I'm happy with my choice. So far I can't speak to any mileage gains, but I'm just going to bet it will improve that too--I just haven't driven it enough yet to notice (only ten miles on the plugs as of now)--but I will update this thread before long to give an idea of any improvements.
I'm also running a K&N drop-in, HCF delete and have my tires inflated to about 40lbs in hopes of milking every bit of MPG that I can.
__________________
2004 SR5 4WD V8
, Titanium Silver, sunroof, HCF delete, K&N drop-in, Interior 6000K LED swap, map light mod, Denso Iridium TT 4702 spark plugs, Hankook DynaPro ATM tires, SilverStar Ultra lows/highs/fogs.