In 1998 Mercedes re-branded coupe versions of its famous S600 as CL600, eliminating confusion among buyers and enthusiasts. Outside of that, there were few changes to the S600 in the 1998 with a major overhaul of the vehicle planned for the 2000 model year.

The S600 remained the premier car in Mercedes' premier lineup. BrakeAssist and BabySmart were added as standard safety features, and the vehicle retained its 6.0-liter V12 engine, 389 horsepower, 420 foot-pounds of torque engine.

There were minor complaints about the cars gas mileage, but on the whole drivers had positive feedback for the 1998 S600. "This is the finest car I have ever driven," claimed one owner.