This Case study has developed a comprehensive method to minimize Rust formation on Diesel fuel Tank coating surface & its effects by using ALSi sheet and field failure analysis by using testing, validation to find out Root Causes.also concept design & packaging Double fuel tank after E-commerce segment study. The aims of this project are mainly cover the General, Technical & Dimensional specification, safety concern of fuel tank assembly, Concept 3d cad modeling, calculation, 3D CAD simulation, fuel tank manufacturing Process sequence chart, tentative process costing and its practical field failure analysis. The Research is mainly concerned to compare metallic fuel tank with diffrant coating Surfaces like GA & Alusil for rust formation study.This project applies to commercial vehicles segment of automotive industry consisting mainly of bus & truck segment. And also covers the various study To get insight on underlying segment behaviour, Product usage, Product Performance in E-Com segment and exploring the product opportunities with additional fuel capacity that is win-win E-Com Segment customer.