Are the 8's using plugs that differ from the 7's or are they using the same ones? Ive heard that there suppose to be smaller, id imagine the thread size is the same, anyone see any potential with using these plugs in a 2nd gen?

 

A total waste of money. Run stock NGK 7's and 9's or all 9's if your car is making more than 300hp.

 

My experience:
Trailing - NGK BUR9EQ - ~18,000 miles $6 at Advance auto parts
Leading- NGK BUR7EQ - ~6-9,000 miles $6
Leading- NGK BUR7EQP - ~18,000 miles $7 at Advance auto parts

 

I couldn't find the NGKs at any of my local auto shops, I had to order them from mazdatrix! But yea the engine in the rx8 is the same as the one that we have, the 13b, and from what I can gather from that is that the plugs are probably the same.

 

I was reading through silver bullets rx7 site and was reading about plugs and...

http://www.silverbulletrx7.com/plugs/index.html
"BRISK could surpass all these plugs though and turn out to be the Holy Grail. Only time will tell. There are also rumors that the plugs used in the Rx-8 are producing some awesome results so expect a review on them soon as well. They are NGK iridium plugs though I have not yet seen a part number."

So what the deal then?

 

The last price I saw on the iridium plugs was like $33 each!!

 

Yeah, dealer is like $33 each for the iridiums (most car parts stores don't have them yet)

 

$33.00 per plug what a waste

 

33 a plug, they better last damn near 6 times as long or give me an extra 20hp.

 

i decided to spring for the iridium plugs (leading only) since my leadings were already significantly rounded and worn down after only about 4,000 miles. i wont go out and say they make gobs more horsepower, but the reving is a fair amount smoother. it baisically feels better than when you get a fresh set of ngk's and its lasted that way for about 3,000 miles now, wheras the ngk's (standard, dont know about platinum) noticably slope off after just a few thousand miles.

 

that was a great link and subsequent writeup

 

The rx8 plugs are the same size/ pitch. They are iridium and are air gap insted of SD. The trailing plugs are also shorter then the leadings for some reason. They fit all gens of rx-7.