Lightweighting, also known as vehicle weight reduction or mass reduction, poses one of the greatest challenges to the automotive industry. Automotive manufacturers and suppliers face tough requirements regarding vehicle weight reduction and its impact on fuel consumption, carbon dioxide (CO2) emission limits and manufacturing costs.

Fuel economy targets are becoming ever more important for consumers as they expect from the next car they purchase to achieve a much better level than the last one they owned. By 2021, new cars in Europe should emit no more than 95g/km of CO2, representing a reduction of 40% compared with the fleet average of 158.7g/km in 2007. At the same time, CAFÉ regulations in the US will require light vehicles to achieve 54.5mpg by 2025. These developments make manufacturing costs more important than ever. With approximately 87 million vehicles sold in 2015 and this number expected to rise to 115 million by 2030, introducing lightweight materials and innovative processes will enable car manufacturers to meet these ambitious targets.

Lightweighting has become prominent with an increasing number of parts and components. The body-in-white (BIW) – the stage of manufacturing during which the unpainted sheet metal components are welded together to form the vehicle’s body – accounts for approximately 50% of weight saving potential. In today’s car-body engineering, the primary materials used are aluminum, high and advanced high-strength steels. However, there are many new materials which are stronger and have enhanced performance as well as numerous materials currently under research and development which could be successfully used in lightweighting in the future.

One of the important manufacturing processes to reach this goal is hot stamping, implemented to produce ultra-high-strength steels which are used for bumper beams, reinforcements for doors, A and B-pillars, as well as for parts in the floor and roof of the vehicle. Replacing conventional cold formed parts with hot stamped parts can reduce the weight of the part by up to 50%. In particular, the tailored tempering process gains in effectiveness as it allows for the engineering of stamped parts with targeted local strength properties.

All these materials and innovative processes enable car manufacturers to design lighter cars that fulfill increasingly more stringent safety requirements. However, the application of these materials and processes poses additional challenges since the material selected for each automotive stamped part must be suitable for its particular requirements. Therefore, a successful lightweighting strategy involves much more than the simple replacement of steel parts with lighter materials. The key to successful lightweighting is using the right material for the right part in the right place in a car.

Further information on lightweighting at AutoForm:

Hemming of Thin Gauge Advanced High-Strength Steel

Tailored Tempering

AutoForm Training for Material Behavior in Sheet Metal Forming