Many new Audis also have a newer version of Quattro (marketed as Ultra) that mechanically disengages the rear drivetrain. My A6 wagon gets about 10mpg on the h

Many new Audis also have a newer version of Quattro (marketed as Ultra) that mechanically disengages the rear drivetrain. My A6 wagon gets about 10mpg on the highway better than my in-laws Outback, and I assume this was a large portion of the reason.