This might sound really dumb but since I am new to truck maintenance this may not be so dumb after all: I am posting pictures of an air filter from my 3rd gen Dodge Dakota that i bought recently. I just replaced this air filter. My question is: Does this filter look really dirty or just dirty or just normal? I went ahead and replaced it with a new one. Should it have been replaced? Also what's the red line at the center?

 

Looks normal. Moved your post to the 3rd gen Dakota section for you.

 

Don't know what the red line is. Maybe the manufacturer was at the end of a roll of media.Who knows,it's not going to affect filtration.

Your filter looks normal as in its trapped some fine particulate which is good and shows that it is doing it's job. If you can see a drop light held to the backside and can see the light through the filter it is generally still comsidered serviceable. It's never a bad idea to put in a fresh filter when in doubt.Just be sure no dirt makes it past the seal around the edges and all the clips are in place to hold the cover down against the seal.