just got back from a trip to the coast approx 300 miles.
some in town slow down driving on the interstate but mostly 65 to 70 mph driving. used cruise control about 80% of the time. i was real pleased with 23 miles to the gallon w my 04, a4.
on my most recent trip from seattle to provo, ut, i drove a touch over the speed limit on the way down and got 28 on the best round. on the way back i was less patient and had the ac on for a good portion. sometimes speeds were around 90 and i got 26. not bad at all! any time i do much driving in town at all, it goes down quick. city driving gives me around 17-18.
City is about 17-18. On the highway with A/C on and cruising at 80-85 on several long trips I averaged 23-24. These numbers were calculated using the exact gallons used from the pump, not the DIC. They usually matched though.