Do you guys really drive only 120 on rural autoroutes?
My driving experiences in Canada....okay mostly Québec only, are that everyone's happy floating around 130 or a hair above outside urban areas. I mean, that's what I do too on the autoroute outside developed areas.
Perhaps it is because I've pretty much driven mostly German cars in my driving career, but I've always expected reasonable consumption numbers under "normal autoroute speeds", by definition, 130-140km/h which is pretty standard worldwide. With the old X3, it had its "sweet spot" drinking around 8,5 to 9 l/100km at 120-130km/h. Only above 150 did the consumption curve ramp up very quickly. Even now when I drive mother's 325i, it's actually not all that thirsty doing 130-150km/h; if I hold 130-140 then consumption runs around 8,2 l/100km which is fine (variance of 12% from ECE stated figure). So the expectation is that there will be not a big tradeoff when I drive at a normal speed for long distances. Air Con is not so much an issue; I don't really use it much.
Yes, I was able to attain the official 6,1 l/100km stated combined figure for the Mazda3, if I drove at 100km/h on a totally level surface. But two problems: 1) I don't live in a flat area at all and 2) 100km/h is for rural roads, not autoroutes. And weirdly, the active grille shutters open above 140km/h- yes I read the service manual-, kind of defeating the purpose. So yes, if my long-distance driving was solely rural roads, then consumption would be in the mid 6s, which is acceptable.
And perhaps if your driving is all suburban, then the Skyactiv engine is less disappointing. It is thrifty in suburban driving (the 50-90 km/h range) but my driving profile is 80% autoroute and the remaining urban (as in, city centre, parallel parking, 50km/h). And rural autoroutes for me mean a set limit of 130 km/h or sometimes none at all in certain secteurs. And the turbocharged motor in the Tiguan isn't that thirsty at speed, the averages were pretty good- too bad the gearbox is rubbish for North America.