What is the mpg city and highway?
Here you go: http://www.fueleconomy.gov/feg/bymake/Audi2004.shtml
That depends on the model. Check www.edmunds.com look for "specifications" of the year and model you are interested in.
Search Audi A4 Avant Questions
Audi A4 Avant Experts
Related Models For Sale
Used Cars For Sale