Hello to everyone. I own several chevys but my newest one is a 2011 chevy duramax. I have been reading on cold air and exhaust for my LML. I love this truck. Yes it is my first diesel. There is mixed opinions on both. Not sure which one to get. I would like better mileage and power but i know one is a trade off for the other. Where can i get the best information for what i am looking for? I know members on this site have there choices. I am looking for proven information from members in what they used and what they gained or did not gain. I have had my 2011 since August of 2011 and have put miles on it stock. Any information will be appreciated.