Mercedes has decided to abandon the complex sandwich platform in the A-class. But why?The move is at the heart of a planned range expansion that will also mean the end of the bespoke four-cylinder engines used only in the A-class. Used since the introduction of the A-class back in 1996, the costly sandwich structure was originally designed to accept batteries within its flat floor. “The advantage of the new platform is it allows a lower seating position,” says an insider privy to Mercedes-Benz’s small car plans.“Until now we have been compromised in terms of the number models we could base on the structure owing to the height of the floor.” The new platform will be cheaper to produce – something that will help Mercedes to obtain a greater return on the notoriously expensive-to-produce A-class.The decision to go with a new platform will also heralds the end of Mercedes-Benz’s four-cylinder M266 (petrol) and OM640 (diesel) engines. Produced expressly for the A-class and B-class, they boast a unique design that allows them to be mounted below the floor for improved cash protection. Instead, the new models are set to run new four-cylinder M270 (petrol) and OM651 (diesel) engines closely related to those found in the C-class.Mercedes claims they will provide greater production flexibility and much improved economies of scale. “There will be a high level of technical integration among the four new vehicles, which are also going to benefit from the modular system used by the other Mercedes passenger-car model series,” said an Autocar source.“A case in point is the new generation of Mercedes four-cylinder diesel engines, which is having its market premiere in 2008 and which will also be available for use in the new vehicles.”Other developments include plans to equip each of the new models with fuel saving features such as start/stop and brake regeneration. Internal documents seen by Autocar suggest Mercedes will provide its new small cars with a hybrid option using the lithium-ion batteries in next year’s S400 hybrid. But the sandwich structure could be used on a range of electric vehicles in the future. “There is no better basis for an electric car,” says Thomas Weber, head of research and development. “I don’t think you have heard the last of it yet.”To provide sufficient production capacity for its new price-leading models, Mercedes says it has earmarked a further €600 million to upgrade its existing Rastatt manufacturing plant in southern Germany.In a landmark move, the German car maker also plans to establish a new low-cost plant in Kecskemét, Hungary, in a move it claims will “boost competitiveness” and provide “access to new markets”.