A firm fixture in the product range of a Swedish furniture store since 1979 and sold more than 41 million times since then – the "Billy" shelf has long since become a classic piece of furniture. And it was very much in demand as an extra during the testing of the new smart generation under realistic conditions: two Ikea "Billy" shelves (2.12 m, with boxes) fit in the smart forfour, plus a yucca palm (around a metre high) and four small moving boxes. This little car is truly great – but that was no surprise for the brand's packaging experts as they used CAD data of the vehicle and the shelving to simulate transporting such furniture in advance. From a golf bag to a snowboard with accessories – lots of further loading scenarios were tested in this way on the computer and in practice.

And when it came to measuring the cargo capacity in litres, the developers used more than just the standardised blocks with an edge length of 200 x 100 x 50 mm as specified by the Association of the German Automotive Industry (VDA) and regulations DIN 70020-1 and ISO 3832. The luggage compartments of the smart fortwo and smart forfour were naturally also tested with crates and bottles. Taking the permissible gross vehicle weight into account up to five crates of water each with nine 1 litre PET bottles can be transported in the smart fortwo – a total of 45 litres of water.

For the four-seater the developers spent time shopping and working not only with beverages, but also in the hifi department. A 42-inch flat screen including packaging (1150 x 735 x 132 mm) fits diagonally on the rear seats if the readyspace seats (option) have been turned around. Thanks to the rear doors that open at an angle of almost 90°, larger items such as a screen like this are simple to stow inside the car.

But in daily driving it's often the numerous small accessories such as ice scraper, drinks or travel guides that need to be stowed away somewhere rather than large objects. Ideally in such a way that they are within easy reach of the driver or passenger but without presenting a danger to passengers in the event of an accident. The smart developers used an extensive shopping basket to ensure that the cars are designed to accommodate such small items ergonomically and also safely.

The list of objects in the shopping basket comprised more than 70 different items based on a general assortment from Mercedes-Benz Cars and supplemented by model-specific products such as 1.5 litre bottles. A distinction was made between three areas: driver, passenger and – for the forfour – rear passengers, and also three access possibilities: direct, indirect and intuitive. The theoretical validation was done with CAD data. Stowage options for each item were then evaluated in a practical test. This meant that it was possible to optimise the position of media connections and cup holders and the design of the door pockets for holding bottles during the development phase.

Here is an overview of loading examples:

smart forfour:

smart fortwo: