What would you delete?

I bought a 2014 Dodge Ram 2500, with the Cummins diesel, about a year ago. It was from Canada, so when I titled it in Michigan, I lost the factory warranty. ( Seemed odd to me, but I have made all the calls to the company in Canada and US). I love how it runs (had a Ford 6L before this, enough said) but want to hold onto this for a while so I figure should find out what deletes will give most benefit. Not worried about more power, but a little mpg would be great. The biggest thing is about improving longevity. It has 47K on it now, so it seems to be a good time to do the delete. Thanks for any ideas.