no idea if really needed but followed the lexus recommendation of every 40k.

 

if anyone sees anything that should be addressed....

 

they look perfectly normal.

 

Second from right looks a bit too oily, but this may be just the way picture shows.

 

I replaced mine about 2 weeks ago. They looked just like yours. I also checked the gap. It was still in tolerance. The car runs the same with the new plugs.

 

The middle two look more worn out than the others, but look normal to me.

 

Not too bad, little bit of blow by on the tops of the plugs too (as is typical on turbocharged engines). Electrode wise they look okay, but the engine does run a bit rich hence the blackening. I can see why they recommend this sort of change interval, while they are definitely not finished, they aren't as clean as what you'd get on a naturally aspirated engine at that mileage. You could probably push them another 10-20k without too much loss in efficiency.

 

Someone needs to come up with plugs designed specifically for high compression engines.
They all have exhaust leak past insulator.
#3 from the left is covered in oil, so there is internal oil leak from somewhere.
#1 is following suite, just not as bad.

 

I have read engine oil is responsible...mainly calcium additives. this area I have no clue, but engine oils are different.