Depending on the cost of gas vs. diesel and how much your drive the
diesel will eventually take care of it's self. The care and feeding of
a diesel is more expensive than a gas. For example on a diesel you need
to change the oil about twice as often and the diesel takes about twice
as much oil and the filters cost about twice as much.
I ran the numbers and took all this into account and the diesel will
pay for the extra initial cost in about 80 to 100 thousand miles. After
that it's all gravy.