How do you determine age of plugs/wires?

[Bucky1]

2011 Denali XL
Just bought it a few months ago. 102000 miles. Pulled a plug, and it doesn't look new. But still has .040 gap on the irridium type plugs. Wires look fresh. But maybe the dealer cleaned them nicely.
How do you know?

 

[Tonyrodz]

2011 Denali XL
Just bought it a few months ago. 102000 miles. Pulled a plug, and it doesn't look new. But still has .040 gap on the irridium type plugs. Wires look fresh. But maybe the dealer cleaned them nicely.
How do you know?

If you're not sure, they're cheap enough to just replace them. Even for just peace of mind.

 

[swathdiver]

Maybe someone changed them at 100k? Is it running smooth and getting the mileage it's supposed to? What part number are the existing plugs and wires, that can sometimes tell if they've been replaced or not.

 

[drakon543]

depending on the wire quality and installation this is usually what i go with. if i just bought it i change them regardless so i know they are good and when they were last changed. if the plugs are starting to show rust and the porcelain is beginning to discolor ill change the plugs. for the wires if i have a color other than black i check for discoloration on the wires. also check the boot to see if it feels brittle or hard then i change them. as for my normal maintenance most standard plugs and wires are fairly cheap so every 2 or 3 years regardless of mileage.

 

[Bucky1]

Plugs looked so so. Wires really good. Think I will change this winter just for piece of mind. It runs well.
Sorry guys I put this post on the wrong year section.

 

[drakon543]

no worries i dont usually bother with sections. i just surf through new posts until something peeks my interest.