It’s been about a month since I purchased the facelifted Mercedes-Benz R231 SL400, and with over 1,000 kilometers on the odometer, I’d like to share a detailed review. Riding in the SL—a luxurious two-seater convertible that Mercedes proudly offers—after a long time, what struck me most was its overwhelming sense of refinement.

The reasons behind choosing the SL were covered in my previous post, but what surprised me first after getting behind the wheel was its extraordinary ride comfort. Among the many cars I’ve driven, few deliver this level of smoothness and luxury.

The Magical Ride Created by Active Body Control

The ABC (Active Body Control) system equipped on the R231 SL400 is truly a testament to Mercedes’ engineering prowess. While it has since evolved into Magic Body Control, even this generation’s ABC delivers more than enough performance.

You can feel the brilliance of this system from the moment you start driving. It behaves somewhat like an air suspension, but in reality, it’s a hydraulically operated suspension system. It instantly adjusts the ride height of all four wheels using hydraulic pressure, absorbing even the smallest road imperfections with remarkable finesse. The sensation is like the body floating and gliding effortlessly above the road, offering an unmatched level of refinement.

The control logic is quite similar to the Porsche Active Ride system installed in our Taycan Turbo GT, though the latest Active Ride technology has a slight edge in suppressing body roll. Considering the R231 debuted over a decade ago, Mercedes’ foresight in commercializing such advanced tech back then is truly impressive.

Interestingly, the R231 has no stabilizer bars at all. The bold design philosophy relies entirely on Active Body Control for handling. High-frequency vibrations above 6Hz are managed by conventional dampers, while low-frequency vibrations below 5Hz are absorbed by the hydraulic units. This clever division of labor creates a ride quality that, while different from the perfectly flat feel of the Turbo GT, is on a whole other level of comfort.

Versatile Driving Modes for Dynamic Performance

The SL400 offers four driving modes: Comfort, Sport, Sport Plus, and Curve. The Curve mode is particularly impressive—it raises the outer wheel height during cornering to significantly reduce body roll. Similar to Porsche’s Active Ride, this system allows smooth cornering without subjecting passengers to uncomfortable lateral forces.

However, Curve mode can feel a bit unsettled on straight highways. In such cases, the normal Comfort mode is more suitable. Curve mode is truly designed for enjoying twisty mountain roads in comfort and style.

In city driving, starting off in second gear in Comfort mode feels exceptionally smooth. The 9-speed automatic transmission, introduced in the facelifted R231, is excellent—delivering seamless acceleration even in stop-and-go traffic. This smoothness is a uniquely Mercedes trait, quite different from the sharp shifts of Porsche’s PDK.

The Perfect Power Balance of the M276 Engine

The 276-series M276 engine powering the SL400 is a 3.0-liter V6 twin-turbo also found in AMG C43 models of the era. With 367 horsepower and 500 Nm of torque, it’s not exceptionally high-powered by today’s standards, but it boasts a character focused on strong low- to mid-range torque.

What makes this engine special is its straightforward throttle response, something rare in modern engines. Many contemporary powerplants feel artificially controlled at low speeds to optimize fuel economy, but the 276 strikes an ideal balance—delivering ample torque from low revs while still being fuel-conscious.

In Comfort mode, the engine behaves very calmly, allowing you to drive like a regular passenger car. It provides predictable acceleration at any speed with minimal lag. Switch to Sport mode, and the engine transforms. It’s not loud or aggressive, but it produces a presence and sound that’s surprisingly assertive for an SL.

The tone is refined and well-rounded, especially enjoyable when cruising between 2,000 and 3,000 rpm. There’s no need to rev it high like a hardcore sports car—this relaxed character is the true charm of the 276 engine. Sport Plus mode offers even more aggressive tuning, but Sport mode strikes the best balance for mountain roads.

While the SL400 is said to perform close to the earlier R231 SL500, it’s definitely quicker than the R129 I previously owned. The R129 was more about enjoying the legendary feel of its 5.0-liter V8, but in terms of practicality, the SL400 takes the crown. The M276 engine is truly worthy of being called a modern classic.

In the next installment, I’ll share impressions of open-top driving, handling characteristics, and highway performance.