They probably changed to 100k for 14's by using switching plug type.
I dont mind taking a look at the plugs every 30K or so But for me that wont be for 4-5 Years unless something in my life dramatically changes

STEVE

 

Its not because the plugs fail. Its an emissions requirement due to the hemispherical style combustion chambers hiding fuel. This is why it requires 2 plugs per cylinder. Change yours when you start to see hydrocarbons rise on your emissions test, probably around the 60 - 70k mile mark. All current engines must make a benchmark number of miles before emissions degrade to a certain level. Ill see if I can find the SAE test requirements (if I remember right it was so many HC.PPM per 100k). The last one I saw was in 2008 but I don't assume it has changed much. Here is the EPA requirement link if you happen to have 2 weeks free to read it all. haha. Its crazy to think all these regulations must be met just to get an engine approved for production let alone fuel consumption and drivability/power production.
http://www.ecfr.gov/cgi-bin/text-idx....1.2.2&idno=40

 

Depends on MY. on again/off again nickel/coper/iridium 2x iridium then back to nickel, then back to 1x iridium.

cliff

 

The owner's manual for my 2013 specifies LZFR5C–11G spark plugs, these are standard copper core electrode (they changed to iridium in 2014). At 31K miles I had the plugs changed at the dealer and they replaced them with SPLZFR5C11 which are iridium. I asked the service manager about the replacement schedule for these and he said 100K miles. Check the link below about plug materials; they claim iridium lasts 25% longer than platinum. Make sure to use anti-seize compound because after such a long interval between changes, the plugs may get stuck in the cylinder head.

https://www.championautoparts.com/Pa...Materials.html