On my 2013 Nissan Versa. Looks pretty normal to me. Gap increased to about .048 from new of .043. Already runs smooth with no noticeable symptoms so don't expect any change after replacement.
I see that on three of them the ground pad is eroded. This is a good time to replace them, to make the life of the coils easier.
Larger gap means higher arc voltage and more power dissipated in the coils. Higher coil temperature shortness their insulation life. On any V6, the rear coils (firewall side) are really hot as they are...
Probably, but to what point? Wait until they misfire and eventually damage the coils too?
They are there for 8 years, so the new set will last another 8 years, total of 16 years. Probably the car will be done by then.
If he waits one more year, would push that to 18 years... If he gets rid of the car at 15 years, it won't matter if the next plus could last to 16 or 18 year mark.
I think that 80k miles for a spark plug is fine. I do it myself so the cost for me is just the plugs. Once every 7-8 years is not bad.
I've never tried NGK but, I do have a new set of them, G-Power Platinum, tr55gp's, to go into my 2002 Ford F-150 soon.
It's just way too hot now to put them in! No air conditioned garage! And high humidity makes it a miserable
work place! I'm hoping they do well. I've seen and read many good things about NGK on this site.