The US 1991 300D 2.5 Turbo Sedan was available with optional ASD (Automatic Locking Differential); ASR (Automatic Slip Control) was an option on 300E sedans except the 4-Matic. It was also an option on the TE Wagon and 300CE

In 1992, ASR was a standard feature on the 300TE and 500E, optional on everything else but the 4-Matic

In 1993, it went back to "optional" status, except the 500E