Currently in the same car – just note that you lose roughly 5mpg by using the ACC. At least we do. We averaged around 39-40mpg with ACC, we average 44 to 45 now without (around 25-30 mile journey).
Mine is the manual 1.5 petrol, I get nowhere near that sort of mileage!. Usually around 35mpg, even on my only longer journey (120 miles round trip on mainly A roads) it struggles to get up to 37mpg. Best I can get out of a full tank is around 360-375 miles.
My previous 1.2 petrol manual Yeti was slightly better and that was as aero dynamic as a brick!! 🙂
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!