I found this article while researching what it would take to get 17"x7.5"
Audi A4  wheels to work on my crewcab.

This line caught my eye;" What's immediately apparent from the results is
that as the wheel-and-tire packages get larger and heavier, acceleration and
fuel economy suffer. Neither is a huge surprise, but we measured a
10-percent drop in fuel economy and a four-percent degradation in
0-to-60-mph acceleration from the 15s to the 19s".

I  looked at  these this morning.
http://winstonsalem.craigslist.org/pts/2618213904.html . Nice looking BIG
wheels. Some road rash. He also has the longer lug bolts.

The bolt hole size is good but it appears the center bore (~57mm) would need
to be opened up. I need to actualy take a front wheel off my truck and do
some measuring . I have read the grease cap can be shortened to get rid  of
the lip.

I arrived at a  back spacing of 137.25mm on the Audi wheels . By my
calculations I would need a 14mm spacer? Anyone?

Thanks Ken