I have a 2014 Ram cab and chassis 3500 with approx. 70,000 miles....just bought it and noticed that it is using a lil oil (seems to be down a quart after a couple thousand miles)........I have put it on a lift and find no leaks whatsoever,..tried to run it a lil hard to make it smoke, but no smoke other than one puff of dark black when you accelerate hard..................is this normal?...or what should I look for? (I've had and worked on many cars and trucks over the years, but this is first diesel)