Description
The Mercedes-Benz 320 Cabriolet B 3.4 was the enhanced and more powerful four-seat open-top touring model of the late W142 series, introduced when Mercedes-Benz enlarged the original 3.2-litre engine to 3.4 litres. This updated variant preserved the elegance, practicality and refined craftsmanship of the standard Cabriolet B while adding smoother acceleration, stronger mid-range torque and improved long-distance capability. It became one of the most desirable late-series W142 open models, offering both family usability and elevated performance in a beautifully executed Sindelfingen body.
Power came from the enlarged 3.4-litre inline-six, developing approximately 79–80 horsepower. Although the increase in peak output was modest, the real improvement lay in torque delivery, making the engine more relaxed and flexible at all speeds. It pulled more confidently from low revs and maintained higher cruising speeds with less strain, qualities that suited the Cabriolet B’s touring character. Paired with a four-speed gearbox featuring synchromesh on the upper gears, the engine provided a smooth and steady driving experience, whether navigating city traffic or covering long distances on open roads.
The Cabriolet B 3.4 continued to use the short-wheelbase version of the W142 chassis, giving it compact yet generous proportions for a four-seat open car. The chassis featured a strong box-section frame designed to carry the additional power without compromising rigidity. Independent front suspension with coil springs and a swing-axle rear setup provided the supple ride and predictable handling for which the W142 series was known. Hydraulic brakes on all four wheels gave the car reliable stopping power and contributed to its reassuring road manners. The combination of improved engine performance and well-sorted chassis dynamics made the Cabriolet B 3.4 a particularly capable and comfortable touring companion.
Sindelfingen’s bodywork lent the Cabriolet B 3.4 an elegant and balanced presence. Its design combined a long, flowing bonnet with deep front wings, proportioned doors and a gracefully shaped rear deck that housed the folding roof. The four-seat layout created a slightly fuller profile than the two-seat Cabriolet A, yet the car retained its harmonious lines and understated luxury. The high-quality fabric roof folded neatly and low, maintaining the shape of the car when open, and provided excellent weather protection when raised. Chrome accents and finely executed details reflected Mercedes-Benz’s commitment to craftsmanship and aesthetic refinement.
Inside, the Cabriolet B 3.4 offered a comfortable, well-appointed cabin for four adults. The front seats were supportive and generously sized, while the rear bench provided ample space for passengers, making the car genuinely practical for touring. Upholstery could be specified in fine leather or durable cloth, complemented by polished wood or neatly finished metal trim on the dashboard. Instruments were clearly arranged, and all controls reflected the robust quality typical of Sindelfingen production. With the roof lowered, the interior felt bright and open; with the roof raised, it remained warm and quiet enough for all-weather travel.
On the road, the Cabriolet B 3.4 delivered a refined and confident performance. The enlarged engine provided noticeably smoother acceleration and stronger pulling power, especially on hills or when carrying passengers. The suspension absorbed road imperfections effectively, giving the car the relaxed, rolling gait expected of a luxury open tourer. The shorter wheelbase allowed for more responsive steering than the larger Cabriolet D, making the car pleasant to drive both in town and on country roads. With the roof down, the Cabriolet B 3.4 offered a genuine sense of open-air luxury; with the roof up, it served as a dignified and comfortable all-purpose touring car.
The 320 Cabriolet B 3.4 appealed to buyers who wanted the usability of a four-seat open car combined with the refinement and improved performance of the updated engine. It was more practical than the Cabriolet A and less formal than the Cabriolet D, which helped it achieve a balanced and versatile position within the W142 lineup. As a late-series model, it was produced in relatively small numbers, adding to its desirability today.
Modern collectors regard the Mercedes-Benz 320 Cabriolet B 3.4 as one of the most appealing and well-rounded pre-war open Mercedes-Benz models. Its combination of graceful Sindelfingen design, smooth straight-six performance and genuine four-seat capability makes it an exceptional example of late-1930s automotive elegance. Surviving cars are treasured for their rarity, craftsmanship and their ability to capture the essence of Mercedes-Benz luxury just before the outbreak of the Second World War.