Not de-tuned here, but hopefully tuned for our driving speeds else the mileage at our much lower speeds is poor. Germany needs to put some limits on the Autobahn speeds. which are very bad for the environment and unfortunately sometimes bad for those in the very fast moving cars.
I shake my head and chuckle when I see someone here driving a car designed for twice our speeds, just tooling along here. What a waste of money and a misapplication of technology.
It's not how to drive a Mercedes, it's just that the rich who buy them here are gentle mature drivers who seldom even go on the highway and never in snow; thankfully.