Weight, not software, still wins. Each generation of car carries more steel, more sensors, more screens, and physics punishes that mass through higher inertia and rolling resistance. Even when engines and electric drivetrains improve thermal efficiency or energy density, the gains are partly cancelled because the vehicle must accelerate a heavier structure every trip.
Safety comes first, and it is heavy. Crash-test standards push engineers toward larger crumple zones, stronger body-in-white structures, additional airbags and side-impact beams, all of which raise curb weight and frontal area, undermining drag coefficient gains. Electronic stability control, advanced driver assistance and battery packs add wiring looms, control units and structural reinforcement, creating a compounding effect that marketing rarely mentions.
Comfort finishes the job. Bigger touchscreens, powered seats, acoustic insulation, panoramic roofs and oversize wheels satisfy buyers but degrade energy consumption by increasing mass and aerodynamic drag. Component suppliers sell each part as smart and lightweight in isolation, yet system integration lacks a strict mass budget, so grams become kilograms, and the supposedly efficient car leaves the factory fighting its own bulk.
