In Europe you can pretty much legally cruise on highways at 140 km/h in most countries (with a few exceptions).
At those speeds, my office Hyundai Tucson hybrid (with 65hp less power and 100kg lower mass) has the same fuel consumption as my 2.0 GT Line (which is fully loaded, including sunroof and 19" wheels). That is between 8.3 and 8.5 l/100km.
Also, I got the same fuel consumption with a Mercedes GLC hybrid-DIESEL with 300hp and about 200kg extra mass. But, diesel.
I think the 2.0 Stinger is such a great long distance car. Especially if you have all the comfort stuff like adaptive cruising, heated and ventilated seats, HK sound etc. I'm almost at 200.000km and love it.