My 03 I've owned almost a year, pulled the plugs for the first time and saw half Denso double platinums and the others were NGK G Power. I don't know when they were installed or why they don't match but I've driven 8200 miles on then. NGK looks brand new but the Densos look like horrible crap. The PO evidently sucked at life and I expected to find stuff like this. Some hoses were glued in place, really bad maintenance practice but it is what it is. Just thought I would share my experience anyone debating going a route other than NGK on these cars

 

Could be worse- there's any number of plug brands that are worse than what you found. But OEM-spec NGKs remain the gold standard.

 

I run coppers 2 colder heat range, unsure what brand. Had Iridium IX (stock heat range). They failed running only 295whp on my turbo set-up.

Won't get anything but coppers now.

Sounds like they replaced two of the older plugs with NGK probably because of a misfire

 

I wasn't having any signs of misfire, roughness but I felt it was time since I've fixed/replaced/inspected everything else. It runs fine but I guess I'll just get a set of new NGKs. I just don't understand spending $20 vs $34 or whatever on 6 plugs instead of 2-3 plugs. That's lazy

 

I wasn't having any signs of misfire, roughness but I felt it was time since I've fixed/replaced/inspected everything else. It runs fine but I guess I'll just get a set of new NGKs. I just don't understand spending $20 vs $34 or whatever on 6 plugs instead of 2-3 plugs. That's lazy

 

You have to remember that some of the early Z33s are on their second or third owners. As the car gets cheaper, there's a lot of people who come to own a Z, but know very little about cars. They get confused about the most basic of maintenance items and practices like just replacing some plugs or gluing on hoses is OK to them.

Lazy or ignorant, it all results in a poorly maintained Z, which is a shame.

 

I agree it's a lazy way to fix, but if a shop did it, and the customer only wanted the plugs changed that were completely bad I could understand.