My family took our new TDI SEL Premium for its first road trip. 620 miles over the course of 4 days from SoCal to central California & back on highway 101. I was having fun playing with the turbocharger and cruise control. The tank wasn't quite full when I set the trip odometer, so the 16.7 gallons I put in at the end of the trip was probably more than we used. That calculates out to 37.9mpg. The consumption gauge in the car said we got 44.2mpg. If I didn't drive so aggressively I'm sure we could get 50mpg. This trip included crappy LA traffic, up & down big grades, and smooth open road with constant speed.
I got a good laugh at the "All new KIA Optima Hybrid up to 40mpg" billboard we saw on the way home.