I'm new to Diesel trucks, I just got my 2013 Duramax LTZ about 3 days ago. The truck has ~139,000 miles on it, having done my research the milage isn't too bad! Love the truck, but noticed right off the bat that it has a dial next to the steering wheel that definity isn't stock. I turn up this dial and the truck lays down the power! so i keep it turned down for good purposes and my own safety xd. I checked for blow-by also, and it doesn't seem to have too much other than to spin the cap slightly which I heard was normal.This truck is also a z71 edition truck, and for sure has seen some offroad. I was wondering what else I should maybe look at that I haven't seen yet? What are some things I should do to the truck to make it last as long as it can? This truck is going to be used for towing a boat here and there but mainly for driving. Be easy on me! Thank you.