Opel Laubfrosch

Opel 4 PS Opel Laubfrosch
Overview
Manufacturer	Opel
Also called	1924-25: Opel 4/12 PS 1924-26: Opel 4/14 PS 1927-28: Opel 4/16 PS 1929-31: Opel 4/20 PS
Production	1924–31 119,484 produced
Body and chassis
Body style	2-door Torpedo 2-door Saloon Delivery van
Powertrain
Engine	Straight-4 Thermosyphon water cooled side-valve unit 1924-25: 951 cc 1924-31: 1018 cc
Dimensions
Wheelbase	1924-25: 2,255 mm (88.8 in) 1924-31: 2,510 mm (99 in)

Opel Laubfrosch
Opel Laubfrosch featuring the pre-1928 radiator. Just visible: on these early models the fuel filler was positioned centrally ahead of the windscreen.

Opel Laubfrosch
Opel Laubfrosch: the 'boat deck' style tail on open topped models was a distinguishing feature of the Opel and of the Citroën which it flattered.

Opel Laubfrosch
Opel Laubfrosch open topped four seater.

The Opel 4 PS, popularly known as the Laubfrosch (treefrog), is a small two-seater car introduced by the auto maker Opel early in 1924. Subsequently, various versions of the little Laubfrosch were produced until it was replaced by the Opel 1.2 litre.

Initially introduced as the Opel 4/12 PS, and manufactured at Opel’s Rüsselsheim plant, this was the first German car to be assembled on a Ford inspired production line. It was aimed at the lower end of the German auto market, and clearly intended, by the standards of the day, for volume production: it sold well, with 119,484 produced by the time Laubfrosch production ended in June 1931.

The official name referred to the fact that the car’s engine size gave it a tax horsepower (Steuer-PS) of 4 PS (4 hp). Where a two figure name was used, as in 4/12, the second number is the claimed actual horsepower.

The origins of the Laubfrosch soubriquet are not entirely clear, but may refer to the fact that Opel painted all the early cars green, which by tradition is a lucky colour in Germany. Emphasis on the green colour also served to differentiate the car from the similarly shaped Citroën 5 CV which normally turned up painted yellow and was accordingly sometimes known as the Citron (lemon).

Series production began in May 1924. Initially only a single body type, a simple two door "cabriolet" was offered, and the cars were all green. The 4,500 Mark price was competitive and the performance, for a small inexpensive car, was good. Demand for the cars and positive publicity followed, along with the affectionate soubriquet "Laubfrosch".

The car had a four-cylinder water cooled side valve engine with a claimed maximum output of 12 PS (9 kW; 12 hp) at 2,200 rpm, and a top speed of 66 km/h (41 mph). Drive passed through a three speed transmission to the rear wheels. Alarmingly from the perspective of the twenty-first century the fuel tank in the Laubfrosch was housed along with the engine under the bonnet/hood.

The footbrake operated mechanically on the drive shaft while a cable operated handbrake applied stopping power to the rear wheels. The wheelbase on these early cars was 2,255 mm (88.8 in).

The 4/12 PS was produced through 1924 and 1925, with a few modifications in place for the second year, including a new fashionable "boat-deck" style rear end and a switch over in respect of the brakes so that in 1925 it was the footbrake pedal that operated via a cable linkage on the rear wheels and the hand brake that operated via a mechanical linkage directly on the drive shaft.