Rabbit
Well-Known Member
The j shaped metal piece= ground strapIridiums are much better plugs than the non-iridiums...My 2015 Prius C has iridium plugs, I have 119,000+ miles on the OEM iridium plugs on them and the past 2 days, I have average 58mpg (and 60 of my 76 round trip miles to work and back is Interstate-I only run 65-68mph to and from work on the superslab)...I do need to change them though (supposed to change them at 100,000 miles). The plugs from the NC700 did have carbon buildup on the top thingy (dont know the name of it). However, the iridium tip and the white casing around it doesn't have any carbon buildup. I am keeping the OEM plugs out of the NC700 as a backup....I am sure they can go 100,000 miles (almost the same plugs in my Prius C). The Prius C only has a 1.5 L engine in it, but the little car only weighs 2000lbs.
White casing = insulator (aluminum oxide, not porcelain)
Metal part that has threads on it = shell