Mercedes-AMG might be a popular sub-brand offering performance-focused variants of nearly the entire Mercedes range, but let’s not forget it was once an independent tuner before the merger in the late ’90s. Still, AMG-tuned models were always quite desirable, like the pictured 1991 Mercedes-Benz 560SEL 6.0 AMG being auctioned by The MB Market, featuring an OEM-quality bodykit and substantial performance upgrades.

The vehicle was delivered to Japan in 1991, which was the last year of production for the W126 generation, before it was replaced by the more modern-looking W140. It is not clear if the AMG conversion was done immediately after purchase or at a later date, but the finished model was imported to the US in 2018 and currently has 72,945 km (45,325 miles) on the odometer.

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The 560SEL was originally finished in Black Pearl, but it was later repainted in Astral Silver, contrasting the black leather interior. More importantly, the period-correct AMG bodykit remains in mint condition, including the sporty body-colored bumpers, side skirt extensions, and the prominent rear spoiler. The model is also fitted with 3-piece AMG Aero III alloy wheels by OZ racing, and twin exhaust pipes at the back, distinguishing it from any other S-Class from the same era.

The S-Class might be four decades old but as a Mercedes flagship, it comes with a luxurious and well-equipped interior. The leather-upholstered seats are heated (front and rear), with electric adjustments and memory function for the driver’s seat, automatic climate control, power tilting sunroof, and cruise control. There is Burl wood trim on the dashboard, center console, and doors, with additional wood pieces added by AMG including the gear shifter and the folding tables on the seatbacks. Finally, AMG branding on the Momo steering wheel, the instrument cluster with a 300 km/h speedometer, and the metal plaque on the center console make sure the driver knows what lies under the bonnet.

Speaking of the engine, it is a modified V8 engine uprated by AMG from the stock 5.5-liters to 6.0-liters and converting it to a twin-cam with four valves per cylinder. The mill produces around 380 hp (283 kW / 385 PS) and 410 lb-ft (556 Nm) of torque. This does not sound like a lot for today’s standards, with the outgoing V8-powered S63 producing 612 hp (456 kW / 620 PS) in stock form, and the upcoming electrified S63e expected to produce even more than that.

Still, it represents a healthy increase over the 275 hp (205 kW / 279 PS) and 317 lb-ft (430 Nm) of torque of the stock 560SEL, figures already impressive from an era when performance sedans had yet to be popularised. Power is transmitted to the rear axle through a four-speed automatic gearbox, where we find a Torsen limited-slip differential and a reinforced rear subframe.

According to the listing on The MB Market, the car was last serviced in 2021, when it received fresh fluids (oil, coolant, brakes, and transmission), plus a new set of brake pads and rotors. The new owner will get the original AMG brochure alongside the leather pouch with the factory manual printed in Japanese. At the time of writing the highest bid was $130,000.