1929 – 1931: Opel 4 / 20 PS
http://en.wikipedia.org/wiki/Opel_4_PShttp://en.wikipedia.org/wiki/Opel_4_PSAt the end of 1928 the claimed maximum power from the engine increased to 20 PS (15 kW; 20 hp) at 3,500 rpm which pushed the listed top speed up to 77 km/h (48 mph). This was accompanied by a further change in the carburetor specification. Three seater bodies had by now disappeared from the list, but a new 2+2 cabriolet was introduced in 1930.
The naming convention by which the Laubfrosch had been known as the Opel 4 PS became in one respect obsolete in 1928, since it defined the car in terms of its tax horsepower (Steuer-PS). 1928 was the year in which the German finance office switched from levying annual tax according to “tax horsepower”, taxing cars instead according to “Steuer-cm3” (tax cubic capacity). Many German cars continued to be named formally or informally according to tax horsepower through the early 1930s, but already in 1931 the Laubfrosch was sometimes known simply as the Opel 1.1, reflecting its engine size in litres rounded to the nearest 100cc, and following the naming convention which Opel adopted across their range in 1931.
New in Norway in 1930. Used to 1936. Stay in barn to 1994. Restored in 1994-95. I am 3`d owner.