– Nice, France

The Greek word katabasis is defined as “a retreat, especially a military one.” It was coined to describe the long, humbling eviction from Persia of the “Ten Thousand” Greek mercenaries hired by Cyrus the Younger, after Cyrus was killed in battle. The word literally means “going down.”

Such heavy historical intro is occasioned by one line in the spec sheet for the 2017 Mercedes-AMG SLC43: a 0-60 mile-per-hour time of 4.6 seconds. The 3.0-liter, twin-turbo V6 SLC43 being 44 horsepower and 4 pound-feet of torque down on the naturally aspirated 5.5-liter V8 SLK55 it supersedes did not ruffle one barbule on one feather. The fact that the SLC43 is 0.1-seconds slower at America’s second-favorite acceleration test (after our beloved quarter-mile) compelled us to call for backup to verify we weren’t delusional.

That fraction of a second is an attack on the foundations of our modern car theses, which dictate that smaller, less-powerful engines are admissible, but under no circumstances do you ever go slower. Not even by a tenth of a second. The future demands more, and to give it less is beyond mere retreat, it is capitulation. Remember when Vader questioned the dark side? Remember how that worked out for him?

In this case, however, it makes for a better car.

You’ll need a deep knowledge of Mercedes product to recognize it, though. Having spent so much time in the engine bay and rationalizing the product line – the SLK250 vamoosed last year, the 3.5-liter V6 SLK350 meet...