[gambiting]

No, just driving on the motorway, at a solid 140km/h. Did the exact same drive in winter and in the summer just this year and that was the difference in consumption(I want to add that I can see the difference in daily use too, but I just happened to do the exact same 700km drive where the only different factor was the season of the year, so it gave me a very good reference point for specific numbers).

[adrianN]

It's even worse for city drivers doing short trips. The engine doesn't have time to heat up properly before you reached your goal. Fuel efficiency is abysmal and the exhaust treatment systems barely work.