Glas Isar

The car that appeared at the 1957 Frankfurt Motor Show was a prototype which in the event differed significantly from the car that entered production the next year, in that it used front-wheel drive. In most other respects, notably regarding the two-cylinder, boxer engine and the overall shape of the car, only minor stylistic changes differentiated the cars that went into production in 1958 from the 1957 prototypes.

The front wheel drive prototype was unstable, however, as the engine was mounted far ahead of the front axle, high above the front-wheel drive power train, in what was a relatively light weight car. Setting the engine further back in relation to the front wheels would have involved a level of re-engineering for which neither time nor money were available. The decision was therefore taken to switch to a rear wheel drive configuration. The late decision led to issues with the gear box, however, which could not be redesigned at this stage and was simply switched round to allow for the fact that the drive shaft pointed in the opposite direction to that previously envisaged. For the driver, this gave rise to a back to front gear change, with first and third speed gear level positions towards the rear and second and fourth positions facing the front of the car.

The late switch to rear-wheel drive threatened to reduce luggage space, while there was ample space between the bonnet and the low profile boxer engine.^[2] Glas took advantage of this by repositioning the spare wheel beneath the bonnet, in a cradle above the engine.

Series production of the Goggomobil T600 began on 12 June 1958. The new, two-door four-seater incorporated several then fashionable transatlantic styling features including an eye-catching wrap-around windscreen, small tailfins and a two-tone paint finish. The tail lights followed the approximate silhouette of a small key and were said to resemble those on the stylish Opel Kapitän.

Still at this time considered advanced was the car's monocoque steel bodied construction (without a separate chassis), the rigidity of which was enhanced in 1959 through the addition of reinforcing box section lengths on each side of the floor section. The front wheels were independently sprung and the rear suspension followed the usual pattern of the time, combining a rigid rear axle with leaf springing.

The 584 cc boxer motor developed a maximum power output of 20 PS (15 kW) at 5,000 rpm, which provided for a top speed of 98 km/h (61 mph). The car weighed only about 650 kg (1,433 lb) and was reportedly able to reach an indicated 100 km/h (62 mph) in 61 seconds.

Unusually in an economy car of the period, the T600 incorporated a 12-volt electrical system at a time when the contemporary Volkswagens and German Fords would still come with a 6-volt systems for another ten years.^[3]

By the time volume production commenced in August 1958, the T600 had been joined by the more powerful T700. In this car the 688 cc boxer motor developed a maximum power output of 30 PS (22 kW) at 4,900 rpm, which provided for a top speed of 110 km/h (68 mph) and reduced by a third the 0–100 km/h (62 mph) acceleration time.

In order to distance the model from the smaller and more minimalist Goggomobil, and possibly also to try and distract from reliability and structural problems that afflicted early cars, November 1959 saw a name change. The "Goggomobil T600" became the "Glas Isar T600" and the "Goggomobil T700" became the "Glas Isar T700". In the manufacturer's Lower Bavarian homeland, the River Isar is the principal river and would have enjoyed a warm resonance with customers, though subsequently, as the company began to implement an export strategy, it was found that customers in some non-German speaking countries thought the name "Isar" sounded "funny" and cars exported to these markets were branded as the "Glas Isard" which was presumably more marketable.^[4] Isard is the vernacular name for a variant of Chamois living in the Pyrénées, known as a fast runner and agile climber, making it a difficult target for hunters. The Glas Isard cars marketed in continental Europe sported a stylized Isard on the sales leaflets and sometimes as an additional badge on the bodywork.^[5]

The name change was accompanied by the appearance of a three-door station wagon variant which was branded as the Glas Isar K600 or K700, according to engine size.

Early "big Goggomobils" suffered from serious reliability issues, suggesting an excessively rushed development schedule. The aluminium castings that formed the motor housings deformed at high operating temperatures leading to a doubling of the fuel consumption. Even more alarmingly, until the manufacturer inserted extra strengthening sections under the floor, the body flexed so much on bumpy roads that small cracks appeared and, in extreme cases, the panoramic windscreen would pop out of its frame. Teething troubles on the early T600 and T700 models burdened the manufacturer with high warranty costs and severely damaged the reputation of Glas cars in the market place.