<b>QUANTIFYING THE WEIGHT REDUCTIONS OF VEHICLE BODY STRUCTURES THROUGH MATERIAL SUBSTITUTION AND THE IMPACT OF LIGHTWEIGHT ON FUEL EFFICIENCY AND HARMFUL GAS EMISSIONS</b>

<p dir="ltr">Road transportation is one of the major contributors to greenhouse gas (GHG) emissions globally, accounting for a significant share of CO₂ emissions that impact climate change. To achieve global sustainability targets, it is essential to control fuel consumption and reduce GHG emissions from vehicles. Among various strategies, vehicle lightweighting has been a promising and effective approach to enhance fuel efficiency and lower emissions without compromising safety or performance. However, there exists a wide discrepancy in the literature regarding weight savings that can be realized by material substitution. The simulation results often yielded inaccurate weight-saving numbers compared to reality. In addition, contradictory conclusions exist in the literature regarding the energy-saving performance of vehicle lightweighting, principally due to adopting different benchmarks for driving cycles.</p><p dir="ltr">This research addresses the gaps through two key activities. Firstly, Finite Element Analysis (FEA) was employed to analyze a vehicle’s Body-in-White (BIW) structure to quantify the weight reductions of the BIW from material substitutions without compromising the structural stiffness. Secondly, the Powertrain Blockset was employed to assess the impact of the BIW’s weight reduction on energy savings and greenhouse gas emissions reduction by utilizing realistic road profile data. It has been concluded that (1) replacing mild steel with aluminum and magnesium alloy will reduce the weight of the BIW by 36.48% and 47.26% without compromising the BIW’s respective bending and torsional stiffness, and (2) the fuel economy and the polluting emissions can be improved as a result of weight savings Fuel economy increased by 0.09 - 0.11MPG and emissions reduced by 0.06 - 0.11kg for the three I-81 highway road routes considered. In addition, it is demonstrated that road elevation has a significant effect on the fuel economy and GHG emission achieved through vehicle lightweight.</p>