I have owned both auto and manual. The auto would get around 420-460 milesper tank depending on wether I kept it to 70-80 mph on avg. The manual gets around 460-520 miles per tank. Again depending on the 70-80 mph avg. So if you keep the speed to around 70 mph for the trip you should get somewhere in the region of 460 miles per tank. On average 65 litres per fill. So you should get around 31.5mpg if my sums are right for the auto. Compared to around 35.5mpg for the manual.