I know this topic has been beaten to death, but have anyone tried NGK BKR8EIX?
I am looking iridium plugs with projected tip at 1 step colder than stock. I am happy with BR8ES, but I want to try BPR8ES and the iridium version of it which they don't offer. Here are some of the spec I found:

NGK BPR8ES:
14mm, 3/4" reach, 13/16" hex, gasket seat,
JIS height, projected tip, resistor

NGK BR8ES
14mm, 3/4" reach, 13/16" hex, gasket seat, resistor

NGK BKR8EIX:
14mm, 3/4" reach, 5/8" hex, gasket seat,
ISO length, resistor, projected tip, fine wire (0.6mm)
iridium center electrode, tapered cut ground electrode

I see the reach and the thread size are the same, so I think they should worlk the same. The only reason I am looking into a projected tip is that most of teh books that I read saying turbo'd cars likes projected tip more than the regular type plugs; however, I can't find any explaination to it. I guess it has to do with heat, but I thought projected tip tends to get hotter? But may be they cool down faster as well?

FWIW, I found that Champions now offer iridium/platimum hybrig plugs like our stock plugs, "iridium center electrode with platinum tipped ground electrode, 0.40"gap". But for 0.40" gap and it is not recommended to adjust gap on iridium plugs, it might not work on our car at all.... and I don't even know how their part numbers work if I want one step colder.

 

dont use champion........its a lawmower plug.