Finally got around to changing the original plugs yesterday. Truck has 94,000 on the clock. Appearance-wise they look pretty good, however I'm a little concerned with the difference between the passenger sided cylinders (worse) and the driver's side deposits (oily, small charcoal-like chunks).

I replaced the PCV valve at 74k, so that should not be an issue. I do run one catch can on the passenger side, but I can't imagine that having such an effect. Last several oil changes were about 5k apart using Pennzoil Ultra Plat. 5w-30. Other typical maintenance performed (air filter; throttle body cleaning, periodic Techron addition, etc). I use "top-tier" detergent gas. Engine runs fine. Link to full size photo.

Anyone have a similar experience?

 

Here’s what 157,000 mile plugs looked like in my f150



yours wouldn’t worry me a bit.

 

Yow. Thanks.