I was thinking about installing a cool air intake for my 2000 durango with a 318. Is it worth installing, does it give better fuel mileage, and does it add hp?

yes in both not huge amount but every gallon helps

What's the difference between the cool air intake vs. factory intake? My 5.9 has a very big airbox and I replaced the paper filter with a K&N filter. I noticed the intake tube has been routed where it should suck in air from outside the engine compartment. So I would assume the intake would pull in cooler outside air vs, warmer air generated from the engine compartment. I did noticed just the stock K&N filter replacement gave me almost 1 mpg improvement in gas mileage.

I should go work for the company that makes these cool air intakes, then I would be so rich off all the idiots that buy this hocus pocus.

No wait, I wouldn't be able to live with myself or sleep at night after doing that...

I'm more comforable just buying my expensive gas at a rediculous amount per gallon and blaming it on my driving habits.