Fuel consumption. Another observation vs E53

[gen2c4s]

We now have 1100 miles on our 30d m sport and to be honest I feel slightly mislead by BMW. The suggestion is that the new gen X5s are a)cleaner (cant dispute that as I have no way of measuring) b) more effecient, I do dispute this, I tried to drive our car as gently as I could and at 55mph I did see 34mpg on a flat peice of road, as soon as there was mild throttle input this dipped to 29 mpg, then around town this soon dipped to 23mpg. At motorway speeds I see 29mpg. My old e53 managed 34mpg at motorway speeds and at 55 mph and 26 mpg round town. Speed wise there is very little difference so BMW can you please tell me how the E70 is more effecient for me?. No matter which way you cut it my old one was more economical.
One other suprise is that I can actually get 23 mpg out of my Gen 2 C4s around town, so BMW well done you have created a mid range SUV that is actually less effecient, to me, than a mid range sports car. Congratualtions!!!