On a deserted stretch of I-94, we dropped the hammer, and within a handful of heartbeats we were up against the 127-mph speed governor. A slight headwind that was unnoticeable at 80 mph moved the car around just a bit at this clip—­nothing scary, mind you, but a subtle reminder that not even the mighty S500 is impervious to the elements.

Mercedes-Benz CLA sedan will come as both an EV and a hybrid, and feature over-the-air updates and AI-based infotainment.