The Opel 2 Liter, also known as the Opel »6«, is an executive car that was manufactured by Opel. Produced from January 1934, the 2 Liter replaced the Opel 1.8 litre which had ceased production in November 1933. Production continued till June 1937, but the replacement model, the Opel Super 6, was already in production in November 1936, after which production volumes for the 2 Liter were very much diminished.

The Opel 1.8 Liter is a family car manufactured by Opel. Production commenced in January 1931, and continued till November 1933. The Opel 1.8 Liter was the first new Opel to be launched following the purchase of an 80% share in Opel by General Motors (GM), and the first Opel to have been designed and developed by GM in North America.