The CALM team selected the roof structure for a lightweighting study to highlight the possibilities of mixed-material for mass reduction. Three lightweighting concepts were compared to the 2011 Honda Accord roof in mild steel as the baseline. With the latest generation steels the mass reduction was 22%. With a mix of steel, aluminum and composites, the mass reduction was 39%.
The all composite design reduced the mass by 40%.Secondary mass reduction can be achieved by optimizing other parts and systems such as tires, wheels, powertrain, suspension system, braking system, bumpers, fuel and exhaust systems, steering system, and electrical systems and wiring. Future research could include an all-aluminum design, side impact analysis, and a moon roof design.