From function to form, BMW’s Isetta microcar is undoubtedly one of the most unique vehicles in the brand’s history. Few cars with a roundel incite reactions similar to the bubble-top coupe; its unusual 3-wheel (or four, depending on the model) stature, front-facing door, and single-cylinder power plant all join to create a car that is unlike any other. Furthermore, the Isetta’s retrofuturistic aesthetics, peculiar format, and unbelievable efficiency pushed the bubble car to be the best selling single-cylinder car in history.
The Isetta’s origins are Italian, not German as some might assume. In fact, the Isetta was originally born without a Roundel, and didn’t always sport one throughout its life. Born as the brain child of Renzo Rivolta, the Isetta was produced by the Italian manufacturer Iso. Previously known more for their scooters, motorcycles, and pint-sized trucks, Renzo and his brand sought to build a car to match. In 1953, the Isetta was unveiled to the motoring press, sparking the start of a rather unique pedigree.
The story of the Iso Isetta continues, but Renzo Rivolta’s aspirations surpassed the Isetta, and after its debut, Renzo moved on to crafting the Iso Rivolta, a sports car powered by an American V8 clad by a Bertone body, similar in concept to De Tomaso’s Pantera. With new plans in his sights, he sold licensing rights to the Isetta worldwide. Companies in Spain, France, and Brazil all went into production, some under the Iso marque, and others under their own, such as Autocarro, VELAM, and Romi-Isetta, respectively. However, despite the car’s success in the microcar market through the Spanish, French, and Brazilian licensed models, no company came close to the success of the Germans.
In 1954, Renzo Rivolta began discussions with BMW for a licensing contract; however, instead, BMW bought the body tooling for the car, and come production, BMW’s Isetta was a car all its own. From the power plant to the bodywork, it’s said that none of the parts between BMW’s Isetta and the original ISO counterpart are interchangeable.
BMW produced the Isetta in a small number of variants, differentiated by size, engine displacement, and wheel configuration. Initially introduced was the BMW Isetta 250, which carried over much of the styling from the Iso original, but incorporated altered cues that gave it some Bavarian flair. The engine was sourced from BMW’s R25 motorcycle: a 250cc four-stroke single-cylinder lump, combined with a number of changes, from head orientation to a redesigned sump. The engine produced a mere 12 horsepower, meaning the BMW required an agonizing 30 seconds to reach a mere 30 miles-per-hour, and had a top speed of just 53mph. In contrast, BMW’s Isetta did achieve a record-setting 79 miles-per-gallon, a worthwhile tradeoff. The Isetta 250 featured four wheels: two in the front, and two closely-spaced wheels tucked under the rear bodywork. The driveline and running gear combination meant the car could be driven on the streets of Germany with only a motorcycle license.
In 1956, the Federal Republic of Germany revised the classes and regulations for motor vehicles, requiring revision on BMW’s part to comply. The Isetta Moto Coupe DeLuxe was introduced, and its key design element is identified by the enlarged, sliding side windows. The displacement of the single-cylinder bike engine was bumped to 298ccs, earning the car the “300” designation. The increased displacement, combined with a bump in compression, gave the Isetta 300 a full 8% increase in power, a staggering one horsepower, giving a total of 13 for the output.
BMW’s third Isetta model came in the form of the 600, geared towards a wider audience by pairing more power with a more conventional wheelbase configuration, meaning the 600 stands as more a sibling to the original. The wheelbase was extended and widened in the rear, affixed with a trailing arm suspension that went on to find itself in many future BMW sedans. The R67 bike offered its engine to the four-seater , proving an increased output that allowed for a top speed of 65 miles-per-hour.
The final variant of BMW’s Isetta range wasn’t a model in and of itself, but rather a change to the established Isetta 300 model. Sales of the car in the UK suffered until the 3-wheeled version was launched. Perhaps the most notable of the entire line for its atypical running gear, the 3-wheeled Isetta 300 encompasses every feature that helped make the little car truly one-of-a-kind. Sales succeeded for the 3-wheeled variant thanks to laws that allowed the cars to be taxed as motorcycles, and driven with only a motorcycle license.
In all, more than 160,000 Isettas were built and sold, and with a number of makes, models, and characteristics, each car has a story of its own. The Isetta has been cemented as a subject of popular culture, from movies to television, and even Pixar’s “Cars.” The cute ‘bubble car’ may not be a dream car for anyone but the strangest of collectors, but there’s undoubtedly something to be loved about BMW’s strangest creation yet.