I had to do a devilishly short trip of about 6.5 miles for Chinese food (don't ask) that typically involves driving uphill on the highway. Ordinarily you'd get in the mid 40 mpgs even with careful driving. Luckily my engine was warm, I got into S4 within maybe 20-30 seconds of the engine turning on. I was in no rush, so I took the little backroads to cut down on highway driving, and only had to take it a little ways. Primarily uphill, but managed 64.5 mpg on the way there over about 6.5 miles.
But, oh, the way back...
105 mpg over about 6.7 miles of net downhill. I was at 120-130 mpg most of the time near the end, but had to get back up some hills to get home.
80 mpg or so roundtrip.