The original 300 SEL 6.3 was a "sleeper" sedan that combined a luxury chassis with the massive 6.3L M100 V8 from the 600 limousine.
In standard form, it typically produced 451 to 518 hp and up to 630 Nm of torque.
Most modern 63 models use a 4.0-litre V8 Biturbo engine (M177/M178), producing significantly more power than the older naturally aspirated versions. 6.3 AMG
Mercedes Admits It 'Lost Some Customers' After Dropping V-8 in C63
Introduced around 2007, this engine is often called "the 6.3" despite its actual displacement. It is celebrated for its raw, muscle-car character and distinctive, aggressive exhaust note. The original 300 SEL 6
Following the naturally aspirated era, Mercedes-AMG transitioned to smaller, forced-induction engines while retaining the iconic "63" badge to signify top-tier performance.
The badge represents a legendary chapter in Mercedes-Benz history, serving as both a tribute to the brand's first V8 production sedan—the 300 SEL 6.3 —and a label for the modern, high-performance "63" series. While modern 63 models often use smaller turbocharged engines, enthusiasts primarily associate the "6.3" lettering with the M156 6.2-litre naturally aspirated V8 , the first engine developed entirely in-house by AMG. The Heritage: 300 SEL 6.3 (1968–1972) Mercedes Admits It 'Lost Some Customers' After Dropping
It was the fastest production four-door sedan of its era, influencing the creation of future AMG performance models. The Modern Icon: M156 6.2L V8